Run clang-tidy’s modernize-use-bool-literals pass.

This makes it clearer whether an integer or a boolean has to be passed
in this specific call.

48 files changed, 125 insertions, 125 deletions

diff --git a/src/display/drawing-text.cpp b/src/display/drawing-text.cpp
index edfd5eca2..76c392d67 100644
--- a/src/display/drawing-text.cpp
+++ b/src/display/drawing-text.cpp
@@ -306,7 +306,7 @@ void DrawingText::decorateStyle(DrawingContext &dc, double vextent, double xphas
     else if(_nrstyle.text_decoration_style & TEXT_DECORATION_STYLE_DOTTED){
         // FIXME: Per spec, this should produce round dots.
         Geom::Point pv = ps;
-        while(1){
+        while(true){
             Geom::Point pvlast = pv;
             if(dots[i]>0){
                 if(pv[Geom::X] > pf[Geom::X]) break;
@@ -331,7 +331,7 @@ void DrawingText::decorateStyle(DrawingContext &dc, double vextent, double xphas
     }
     else if(_nrstyle.text_decoration_style & TEXT_DECORATION_STYLE_DASHED){
         Geom::Point pv = ps;
-        while(1){
+        while(true){
             Geom::Point pvlast = pv;
             if(dashes[i]>0){
                 if(pv[Geom::X]> pf[Geom::X]) break;
@@ -359,7 +359,7 @@ void DrawingText::decorateStyle(DrawingContext &dc, double vextent, double xphas
         double   x    = ps[Geom::X];
         double   y    = ps[Geom::Y] + poff[Geom::Y];
         dc.moveTo(Geom::Point(x, y + amp * wave[i]));
-        while(1){
+        while(true){
            i = ((i + 1) & 15);
            x += step;
            dc.lineTo(Geom::Point(x, y + amp * wave[i]));
@@ -367,7 +367,7 @@ void DrawingText::decorateStyle(DrawingContext &dc, double vextent, double xphas
         }
         y = ps[Geom::Y] - poff[Geom::Y];
         dc.lineTo(Geom::Point(x, y + amp * wave[i]));
-        while(1){
+        while(true){
            i = ((i - 1) & 15);
            x -= step;
            dc.lineTo(Geom::Point(x, y + amp * wave[i]));
diff --git a/src/display/snap-indicator.cpp b/src/display/snap-indicator.cpp
index 2e329c4aa..79a1191b9 100644
--- a/src/display/snap-indicator.cpp
+++ b/src/display/snap-indicator.cpp
@@ -323,7 +323,7 @@ SnapIndicator::set_new_snaptarget(Inkscape::SnappedPoint const &p, bool pre_snap
                                                      nullptr);
 
             SP_CTRLRECT(box)->setRectangle(*bbox);
-            SP_CTRLRECT(box)->setColor(pre_snap ? 0x7f7f7fff : 0xff0000ff, 0, 0);
+            SP_CTRLRECT(box)->setColor(pre_snap ? 0x7f7f7fff : 0xff0000ff, false, 0);
             SP_CTRLRECT(box)->setDashed(true);
             SP_CTRLRECT(box)->pickable = false;  // See the extensive comment above
             sp_canvas_item_move_to_z(box, 0);
diff --git a/src/display/sp-canvas.cpp b/src/display/sp-canvas.cpp
index 6a38ae3e7..5850cad7a 100644
--- a/src/display/sp-canvas.cpp
+++ b/src/display/sp-canvas.cpp
@@ -1767,7 +1767,7 @@ bool SPCanvas::paintRect(int xx0, int yy0, int xx1, int yy1)
     Geom::IntRect paint_rect(xx0, yy0, xx1, yy1);
 
     Geom::OptIntRect area = paint_rect & canvas_rect;
-    if (!area || area->hasZeroArea()) return 0;
+    if (!area || area->hasZeroArea()) return false;
     paint_rect = *area;
 
     PaintRectSetup setup;
diff --git a/src/extension/internal/cairo-renderer.cpp b/src/extension/internal/cairo-renderer.cpp
index c7cd35eb2..c06119391 100644
--- a/src/extension/internal/cairo-renderer.cpp
+++ b/src/extension/internal/cairo-renderer.cpp
@@ -403,7 +403,7 @@ static void sp_symbol_render(SPSymbol *symbol, CairoRenderContext *ctx)
     ctx->transform(symbol->c2p);
 
     // apply viewbox if set
-    if (0 /*symbol->viewBox_set*/) {
+    if (false /*symbol->viewBox_set*/) {
         Geom::Affine vb2user;
         double x, y, width, height;
         double view_width, view_height;
diff --git a/src/extension/internal/emf-inout.cpp b/src/extension/internal/emf-inout.cpp
index 549d4300e..e34d73cca 100644
--- a/src/extension/internal/emf-inout.cpp
+++ b/src/extension/internal/emf-inout.cpp
@@ -2920,7 +2920,7 @@ std::cout << "BEFORE DRAW"
                 }
             }
 
-            if (0 && strlen(tmp_str.str().c_str())) {
+            if (false && strlen(tmp_str.str().c_str())) {
                 tmp_outsvg << "   <!-- \"";
                 tmp_outsvg << tmp_str.str().c_str();
                 tmp_outsvg << "\" -->\n";
diff --git a/src/extension/internal/emf-print.cpp b/src/extension/internal/emf-print.cpp
index 548caea95..add2f0d37 100644
--- a/src/extension/internal/emf-print.cpp
+++ b/src/extension/internal/emf-print.cpp
@@ -245,7 +245,7 @@ unsigned int PrintEmf::begin(Inkscape::Extension::Print *mod, SPDocument *doc)
     }
 
 
-    if (1) {
+    if (true) {
         snprintf(buff, sizeof(buff) - 1, "Screen=%dx%dpx, %dx%dmm", PixelsX, PixelsY, MMX, MMY);
         rec = textcomment_set(buff);
         if (!rec || emf_append((PU_ENHMETARECORD)rec, et, U_REC_FREE)) {
@@ -1007,7 +1007,7 @@ void  PrintEmf::do_clip_if_present(SPStyle const *style){
         /*  find the first clip_ref at object or up the stack.  There may not be one. */
         SPClipPath *scp = nullptr;
         SPItem *item = SP_ITEM(style->object);
-        while(1) {
+        while(true) {
             scp = (item->clip_ref ? item->clip_ref->getObject() : nullptr);
             if(scp)break;
             item = SP_ITEM(item->parent);
@@ -1029,7 +1029,7 @@ void  PrintEmf::do_clip_if_present(SPStyle const *style){
                 */
                 Geom::Affine tf = item->transform;
                 SPItem *scan_item = item;
-                while(1) {
+                while(true) {
                    scan_item = SP_ITEM(scan_item->parent);
                    if(!scan_item)break;
                    tf *= scan_item->transform;
diff --git a/src/extension/internal/odf.cpp b/src/extension/internal/odf.cpp
index 18092873e..bd036da05 100644
--- a/src/extension/internal/odf.cpp
+++ b/src/extension/internal/odf.cpp
@@ -1696,8 +1696,8 @@ bool OdfOutput::writeTree(Writer &couts, Writer &souts,
     Glib::ustring outputStroke;
     Glib::ustring outputStyle;
     
-    processGradient(item, id, tf, gradientNameFill, outputFill, 1);
-    processGradient(item, id, tf, gradientNameStroke, outputStroke, 0);
+    processGradient(item, id, tf, gradientNameFill, outputFill, true);
+    processGradient(item, id, tf, gradientNameStroke, outputStroke, false);
     souts.writeUString(outputFill);
     souts.writeUString(outputStroke);
     
diff --git a/src/extension/internal/odf.h b/src/extension/internal/odf.h
index e92bc1249..691d6e1f7 100644
--- a/src/extension/internal/odf.h
+++ b/src/extension/internal/odf.h
@@ -311,7 +311,7 @@ private:
     bool processStyle(SPItem *item, const Glib::ustring &id, const Glib::ustring &gradientNameFill, const Glib::ustring &gradientNameStroke, Glib::ustring& output);
 
     bool processGradient(SPItem *item,
-                    const Glib::ustring &id, Geom::Affine &tf, Glib::ustring& gradientName, Glib::ustring& output, bool checkFillGradient = 1);
+                    const Glib::ustring &id, Geom::Affine &tf, Glib::ustring& gradientName, Glib::ustring& output, bool checkFillGradient = true);
 
     bool writeStyleHeader(Writer &outs);
 
diff --git a/src/extension/internal/pdfinput/pdf-parser.cpp b/src/extension/internal/pdfinput/pdf-parser.cpp
index b81d7abcb..5fa21263a 100644
--- a/src/extension/internal/pdfinput/pdf-parser.cpp
+++ b/src/extension/internal/pdfinput/pdf-parser.cpp
@@ -1759,7 +1759,7 @@ void PdfParser::doShadingPatternFillFallback(GfxShadingPattern *sPat,
   saveState();
 
   // clip to bbox
-  if (0 ){//shading->getHasBBox()) {
+  if (false ){//shading->getHasBBox()) {
     shading->getBBox(&xMin, &yMin, &xMax, &yMax);
     state->moveTo(xMin, yMin);
     state->lineTo(xMax, yMin);
@@ -2599,7 +2599,7 @@ void PdfParser::doShowText(const GooString *s) {
   builder->beginString(state);
 
   // handle a Type 3 char
-  if (font->getType() == fontType3 && 0) {//out->interpretType3Chars()) {
+  if (font->getType() == fontType3 && false) {//out->interpretType3Chars()) {
     mat = state->getCTM();
     for (int i = 0; i < 6; ++i) {
       oldCTM[i] = mat[i];
@@ -2644,7 +2644,7 @@ void PdfParser::doShowText(const GooString *s) {
       state->setCTM(newCTM[0], newCTM[1], newCTM[2], newCTM[3], x, y);
       //~ the CTM concat values here are wrong (but never used)
       //out->updateCTM(state, 1, 0, 0, 1, 0, 0);
-      if (0){ /*!out->beginType3Char(state, curX + riseX, curY + riseY, tdx, tdy,
+      if (false){ /*!out->beginType3Char(state, curX + riseX, curY + riseY, tdx, tdy,
 			       code, u, uLen)) {*/
 #if defined(POPPLER_NEW_OBJECT_API)
 	charProc = ((Gfx8BitFont *)font)->getCharProc(code);
diff --git a/src/extension/internal/pdfinput/svg-builder.cpp b/src/extension/internal/pdfinput/svg-builder.cpp
index c8e24a5e1..3fdc3db55 100644
--- a/src/extension/internal/pdfinput/svg-builder.cpp
+++ b/src/extension/internal/pdfinput/svg-builder.cpp
@@ -1255,7 +1255,7 @@ void SvgBuilder::_flushText() {
     Glib::ustring text_buffer;
 
     // Output all buffered glyphs
-    while (1) {
+    while (true) {
         const SvgGlyph& glyph = (*i);
         std::vector<SvgGlyph>::iterator prev_iterator = i - 1;
         // Check if we need to make a new tspan
diff --git a/src/extension/internal/wmf-inout.cpp b/src/extension/internal/wmf-inout.cpp
index db7c9c9ce..bcc8aea85 100644
--- a/src/extension/internal/wmf-inout.cpp
+++ b/src/extension/internal/wmf-inout.cpp
@@ -1252,8 +1252,8 @@ Wmf::delete_object(PWMF_CALLBACK_DATA d, int index)
             d->dc[d->level].style.font_size.computed                = 16.0;
             d->dc[d->level].style.font_weight.value                 = SP_CSS_FONT_WEIGHT_400;
             d->dc[d->level].style.font_style.value                  = SP_CSS_FONT_STYLE_NORMAL;
-            d->dc[d->level].style.text_decoration_line.underline    = 0;
-            d->dc[d->level].style.text_decoration_line.line_through = 0;
+            d->dc[d->level].style.text_decoration_line.underline    = false;
+            d->dc[d->level].style.text_decoration_line.line_through = false;
             d->dc[d->level].style.baseline_shift.value              = 0;
         }
 
@@ -3119,8 +3119,8 @@ Wmf::open( Inkscape::Extension::Input * /*mod*/, const gchar *uri )
     d.dc[0].style.font_size.computed           = 16.0;
     d.dc[0].style.font_weight.value            = SP_CSS_FONT_WEIGHT_400;
     d.dc[0].style.font_style.value             = SP_CSS_FONT_STYLE_NORMAL;
-    d.dc[0].style.text_decoration_line.underline    = 0;
-    d.dc[0].style.text_decoration_line.line_through = 0;
+    d.dc[0].style.text_decoration_line.underline    = false;
+    d.dc[0].style.text_decoration_line.line_through = false;
     d.dc[0].style.baseline_shift.value         = 0;
 
     // Default pen, WMF files that do not specify a pen are unlikely to look very good!
diff --git a/src/inkscape.cpp b/src/inkscape.cpp
index c5089b633..a29b2fad5 100644
--- a/src/inkscape.cpp
+++ b/src/inkscape.cpp
@@ -473,7 +473,7 @@ Application::Application(const char* argv, bool use_gui) :
     Glib::ustring ui_language = prefs->getString("/ui/language");
     if(!ui_language.empty())
     {
-        setenv("LANGUAGE", ui_language, 1);
+        setenv("LANGUAGE", ui_language, true);
     }
 
     /* DebugDialog redirection.  On Linux, default to OFF, on Win32, default to ON.
diff --git a/src/libnrtype/Layout-TNG-Output.cpp b/src/libnrtype/Layout-TNG-Output.cpp
index b9171d27b..dc69934b1 100644
--- a/src/libnrtype/Layout-TNG-Output.cpp
+++ b/src/libnrtype/Layout-TNG-Output.cpp
@@ -323,7 +323,7 @@ Geom::Affine glyph_matrix;
             unsigned lc_index  = char_index;
             unsigned hold_iisi = _spans[span_index].in_input_stream_item;
             int newtarget = 0;
-            while(1){
+            while(true){
                 glyph_index = _characters[lc_index].in_glyph;
                 if(glyph_index == -1){  // end of a line within a paragraph, for instance
                     lc_index++;
diff --git a/src/libnrtype/Layout-TNG.cpp b/src/libnrtype/Layout-TNG.cpp
index b3386926a..a9e70a74b 100644
--- a/src/libnrtype/Layout-TNG.cpp
+++ b/src/libnrtype/Layout-TNG.cpp
@@ -17,7 +17,7 @@ const gunichar Layout::UNICODE_SOFT_HYPHEN = 0x00AD;
 const double Layout::LINE_HEIGHT_NORMAL = 1.25;
 
 Layout::Layout() :
-    _input_truncated(0),
+    _input_truncated(false),
     _path_fitted(nullptr)
 {
       textLength._set = false;
diff --git a/src/livarot/ShapeMisc.cpp b/src/livarot/ShapeMisc.cpp
index f44a326ba..63700e1ba 100644
--- a/src/livarot/ShapeMisc.cpp
+++ b/src/livarot/ShapeMisc.cpp
@@ -163,7 +163,7 @@ Shape::ConvertToForme (Path * dest)
           }
         }
 	    }
-      while (1 /*swdData[curBord].precParc >= 0 */ );
+      while (true /*swdData[curBord].precParc >= 0 */ );
       // fin du cas non-oriente
     }
   }
@@ -316,7 +316,7 @@ Shape::ConvertToForme (Path * dest, int nbP, Path * *orig, bool splitWhenForced)
           //printf("suite %d\n",curBord);
         }
 	    }
-      while (1 /*swdData[curBord].precParc >= 0 */ );
+      while (true /*swdData[curBord].precParc >= 0 */ );
       // fin du cas non-oriente
     }
   }
@@ -527,7 +527,7 @@ Shape::ConvertToFormeNested (Path * dest, int nbP, Path * *orig, int /*wildPath*
           //printf("suite %d\n",curBord);
         }
 	    }
-      while (1 /*swdData[curBord].precParc >= 0 */ );
+      while (true /*swdData[curBord].precParc >= 0 */ );
       // fin du cas non-oriente
     }
   }
diff --git a/src/livarot/ShapeSweep.cpp b/src/livarot/ShapeSweep.cpp
index 4004f183d..53e9d3137 100644
--- a/src/livarot/ShapeSweep.cpp
+++ b/src/livarot/ShapeSweep.cpp
@@ -2496,7 +2496,7 @@ Shape::GetWindings (Shape * /*a*/, Shape * /*b*/, BooleanOp /*mod*/, bool brutal
 		    curDir = true;
 		}
 	    }
-	  while (1 /*swdData[curBord].precParc >= 0 */ );
+	  while (true /*swdData[curBord].precParc >= 0 */ );
 	  // fin du cas non-oriente
 	}
     }
diff --git a/src/live_effects/lpe-fillet-chamfer.cpp b/src/live_effects/lpe-fillet-chamfer.cpp
index a6c8ab90b..6c07f246c 100644
--- a/src/live_effects/lpe-fillet-chamfer.cpp
+++ b/src/live_effects/lpe-fillet-chamfer.cpp
@@ -575,7 +575,7 @@ LPEFilletChamfer::doEffect_path(Geom::PathVector const &path_in)
                         Geom::Path path_chamfer;
                         path_chamfer.start(tmp_path.finalPoint());
                         if (eliptical) {
-                            ccw_toggle = ccw_toggle ? 0 : 1;
+                            ccw_toggle = ccw_toggle ? false : true;
                             path_chamfer.appendNew<Geom::EllipticalArc>(rx, ry, arc_angle, 0, ccw_toggle, end_arc_point);
                         } else {
                             path_chamfer.appendNew<Geom::CubicBezier>(handle_1, handle_2, end_arc_point);
@@ -607,7 +607,7 @@ LPEFilletChamfer::doEffect_path(Geom::PathVector const &path_in)
                 default: //fillet
                     {
                         if (eliptical) {
-                            ccw_toggle = ccw_toggle ? 0 : 1;
+                            ccw_toggle = ccw_toggle ? false : true;
                             tmp_path.appendNew<Geom::EllipticalArc>(rx, ry, arc_angle, 0, ccw_toggle, end_arc_point);
                         } else {
                             tmp_path.appendNew<Geom::CubicBezier>(handle_1, handle_2, end_arc_point);
diff --git a/src/object-snapper.cpp b/src/object-snapper.cpp
index 6d0b3cd7e..6764f351c 100644
--- a/src/object-snapper.cpp
+++ b/src/object-snapper.cpp
@@ -125,7 +125,7 @@ void Inkscape::ObjectSnapper::_findCandidates(SPObject* parent,
                     } else {
                         Geom::OptRect bbox_of_item;
                         Preferences *prefs = Preferences::get();
-                        int prefs_bbox = prefs->getBool("/tools/bounding_box", 0);
+                        int prefs_bbox = prefs->getBool("/tools/bounding_box", false);
                         // We'll only need to obtain the visual bounding box if the user preferences tell
                         // us to, AND if we are snapping to the bounding box itself. If we're snapping to
                         // paths only, then we can just as well use the geometric bounding box (which is faster)
@@ -366,7 +366,7 @@ void Inkscape::ObjectSnapper::_collectPaths(Geom::Point /*p*/,
 
         if (_snapmanager->snapprefs.isTargetSnappable(SNAPTARGET_BBOX_EDGE)) {
             Preferences *prefs = Preferences::get();
-            int prefs_bbox = prefs->getBool("/tools/bounding_box", 0);
+            int prefs_bbox = prefs->getBool("/tools/bounding_box", false);
             bbox_type = !prefs_bbox ?
                 SPItem::VISUAL_BBOX : SPItem::GEOMETRIC_BBOX;
         }
diff --git a/src/object/filters/convolvematrix.cpp b/src/object/filters/convolvematrix.cpp
index 0f9c993f6..28fcb0ba1 100644
--- a/src/object/filters/convolvematrix.cpp
+++ b/src/object/filters/convolvematrix.cpp
@@ -28,7 +28,7 @@
 
 SPFeConvolveMatrix::SPFeConvolveMatrix() : SPFilterPrimitive() {
 	this->bias = 0;
-	this->divisorIsSet = 0;
+	this->divisorIsSet = false;
 	this->divisor = 0;
 
     //Setting default values:
diff --git a/src/object/filters/image.cpp b/src/object/filters/image.cpp
index 4b58ce464..83a185cfb 100644
--- a/src/object/filters/image.cpp
+++ b/src/object/filters/image.cpp
@@ -35,7 +35,7 @@
 
 SPFeImage::SPFeImage() : SPFilterPrimitive() {
 	this->href = nullptr;
-	this->from_element = 0;
+	this->from_element = false;
 	this->SVGElemRef = nullptr;
 	this->SVGElem = nullptr;
 
diff --git a/src/object/filters/turbulence.cpp b/src/object/filters/turbulence.cpp
index b626b2380..6ba3a3eee 100644
--- a/src/object/filters/turbulence.cpp
+++ b/src/object/filters/turbulence.cpp
@@ -23,7 +23,7 @@
 #include "display/nr-filter.h"
 
 SPFeTurbulence::SPFeTurbulence() : SPFilterPrimitive() {
-	this->stitchTiles = 0;
+	this->stitchTiles = false;
 	this->seed = 0;
 	this->numOctaves = 0;
 	this->type = Inkscape::Filters::TURBULENCE_FRACTALNOISE;
diff --git a/src/object/sp-gradient.cpp b/src/object/sp-gradient.cpp
index 1fed2a206..0e3fa8e77 100644
--- a/src/object/sp-gradient.cpp
+++ b/src/object/sp-gradient.cpp
@@ -107,7 +107,7 @@ bool SPGradient::isEquivalent(SPGradient *that)
 
     bool status = false;
     
-    while(1){ // not really a loop, used to avoid deep nesting or multiple exit points from function
+    while(true){ // not really a loop, used to avoid deep nesting or multiple exit points from function
         if (this->getStopCount() != that->getStopCount()) { break; }
         if (this->hasStops() != that->hasStops()) { break; }
         if (!this->getVector() || !that->getVector()) { break; }
@@ -167,7 +167,7 @@ bool SPGradient::isAligned(SPGradient *that)
        matches the default value.
     */
 
-    while(1){ // not really a loop, used to avoid deep nesting or multiple exit points from function
+    while(true){ // not really a loop, used to avoid deep nesting or multiple exit points from function
         if(this->gradientTransform_set != that->gradientTransform_set) { break; }
         if(this->gradientTransform_set && 
             (this->gradientTransform != that->gradientTransform)) { break; }
diff --git a/src/object/sp-guide.cpp b/src/object/sp-guide.cpp
index eb0b27ab4..de15c7bcf 100644
--- a/src/object/sp-guide.cpp
+++ b/src/object/sp-guide.cpp
@@ -48,7 +48,7 @@ using std::vector;
 SPGuide::SPGuide()
     : SPObject()
     , label(nullptr)
-    , locked(0)
+    , locked(false)
     , normal_to_line(Geom::Point(0.,1.))
     , point_on_line(Geom::Point(0.,0.))
     , color(0x0000ff7f)
diff --git a/src/object/sp-item.cpp b/src/object/sp-item.cpp
index 6e4a163dc..59ea0a554 100644
--- a/src/object/sp-item.cpp
+++ b/src/object/sp-item.cpp
@@ -1496,7 +1496,7 @@ void SPItem::doWriteTransform(Geom::Affine const &transform, Geom::Affine const
 
     } // endif(compensate)
 
-    gint preserve = prefs->getBool("/options/preservetransform/value", 0);
+    gint preserve = prefs->getBool("/options/preservetransform/value", false);
     Geom::Affine transform_attr (transform);
 
     // CPPIFY: check this code.
diff --git a/src/object/sp-paint-server.cpp b/src/object/sp-paint-server.cpp
index 79e60d116..9ada0fee5 100644
--- a/src/object/sp-paint-server.cpp
+++ b/src/object/sp-paint-server.cpp
@@ -30,7 +30,7 @@ bool SPPaintServerReference::_acceptObject(SPObject *obj) const
 }
 
 SPPaintServer::SPPaintServer() : SPObject() {
-	this->swatch = 0;
+	this->swatch = false;
 }
 
 SPPaintServer::~SPPaintServer() = default;
diff --git a/src/object/sp-star.cpp b/src/object/sp-star.cpp
index 1375bcecb..235fd32d8 100644
--- a/src/object/sp-star.cpp
+++ b/src/object/sp-star.cpp
@@ -34,7 +34,7 @@
 SPStar::SPStar() : SPPolygon() ,
 	sides(5),
 	center(0, 0),
-	flatsided(0),
+	flatsided(false),
 	rounded(0.0),
 	randomized(0.0)
 {
diff --git a/src/selcue.cpp b/src/selcue.cpp
index 375156412..f7d1cdba6 100644
--- a/src/selcue.cpp
+++ b/src/selcue.cpp
@@ -178,7 +178,7 @@ void Inkscape::SelCue::_newItemBboxes()
                                          nullptr);
 
                 SP_CTRLRECT(box)->setRectangle(*b);
-                SP_CTRLRECT(box)->setColor(0x000000a0, 0, 0);
+                SP_CTRLRECT(box)->setColor(0x000000a0, false, 0);
                 SP_CTRLRECT(box)->setDashed(true);
                 SP_CTRLRECT(box)->setShadow(1, 0xffffffff);
 
diff --git a/src/selection-chemistry.cpp b/src/selection-chemistry.cpp
index 3ecefadde..2108db35a 100644
--- a/src/selection-chemistry.cpp
+++ b/src/selection-chemistry.cpp
@@ -805,7 +805,7 @@ void ObjectSet::popFromGroup(){
         sp_item_group_ungroup(static_cast<SPGroup*>(parent_group), children, false);
     }
     else {
-        toNextLayer(1);
+        toNextLayer(true);
     }
 
     parent_group->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG);
@@ -3064,8 +3064,8 @@ void ObjectSet::toGuides()
     }
 
     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
-    bool deleteitems = !prefs->getBool("/tools/cvg_keep_objects", 0);
-    bool wholegroups = prefs->getBool("/tools/cvg_convert_whole_groups", 0);
+    bool deleteitems = !prefs->getBool("/tools/cvg_keep_objects", false);
+    bool wholegroups = prefs->getBool("/tools/cvg_convert_whole_groups", false);
 
     // If an object is earlier in the selection list than its clone, and it is deleted, then the clone will have changed
     // and its entry in the selection list is invalid (crash).
diff --git a/src/splivarot.cpp b/src/splivarot.cpp
index 08cf9584a..7a3971994 100644
--- a/src/splivarot.cpp
+++ b/src/splivarot.cpp
@@ -2400,7 +2400,7 @@ sp_selected_path_simplify(SPDesktop *desktop)
     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
     gdouble simplifyThreshold =
         prefs->getDouble("/options/simplifythreshold/value", 0.003);
-    bool simplifyJustCoalesce = prefs->getBool("/options/simplifyjustcoalesce/value", 0);
+    bool simplifyJustCoalesce = prefs->getBool("/options/simplifyjustcoalesce/value", false);
 
     //Get the current time
     GTimeVal currentTimeVal;
diff --git a/src/style-internal.cpp b/src/style-internal.cpp
index f1d672fce..429353493 100644
--- a/src/style-internal.cpp
+++ b/src/style-internal.cpp
@@ -2694,11 +2694,11 @@ SPITextDecorationLine::read( gchar const *str ) {
         // This method ignores inlineid keys and extra delimiters, so " ,,, blink hello" will set
         // blink and ignore hello
         const gchar *hstr = str;
-        while (1) {
+        while (true) {
             if (*str == ' ' || *str == ',' || *str == '\0'){
                 int slen = str - hstr;
                 // CSS 2 keywords
-                while(1){ // not really a loop, used to avoid a goto
+                while(true){ // not really a loop, used to avoid a goto
                     hit_one = true; // most likely we will
                     if ((slen ==  9) && strneq(hstr, "underline",    slen)){  found_underline    = true; break; }
                     if ((slen ==  8) && strneq(hstr, "overline",     slen)){  found_overline     = true; break; }
@@ -2833,7 +2833,7 @@ SPITextDecorationStyle::read( gchar const *str ) {
         // this method ignores inlineid keys and extra delimiters, so " ,,, style hello" will set style and ignore hello
         // if more than one style is present, the first is used
         const gchar *hstr = str;
-        while (1) {
+        while (true) {
             if (*str == ' ' || *str == ',' || *str == '\0'){
                 int slen = str - hstr;
                 if (     (slen ==  5) && strneq(hstr, "solid",        slen)){  found_solid  = true; found_one = true; break; }
@@ -2977,7 +2977,7 @@ SPITextDecoration::read( gchar const *str ) {
     test_color.read( "currentColor" );  // Default value
     test_color.set = false;
     const gchar *hstr = str;
-    while (1) {
+    while (true) {
         if (*str == ' ' || *str == ',' || *str == '\0'){
             int slen = str - hstr;
             gchar *frag = g_strndup(hstr,slen+1); // only send one piece at a time, since keywords may be intermixed
diff --git a/src/ui/contextmenu.cpp b/src/ui/contextmenu.cpp
index f66a71cd8..7a6c4e7cf 100644
--- a/src/ui/contextmenu.cpp
+++ b/src/ui/contextmenu.cpp
@@ -94,7 +94,7 @@ ContextMenu::ContextMenu(SPDesktop *desktop, SPItem *item) :
     }
     Gtk::MenuItem* mi;
 
-    mi = Gtk::manage(new Gtk::MenuItem(_("Hide selected objects"),1));
+    mi = Gtk::manage(new Gtk::MenuItem(_("Hide selected objects"),true));
     mi->signal_activate().connect(sigc::mem_fun(*this, &ContextMenu::HideSelected));
     if (_desktop->selection->isEmpty()) {
         mi->set_sensitive(false);
@@ -102,7 +102,7 @@ ContextMenu::ContextMenu(SPDesktop *desktop, SPItem *item) :
     mi->show();
     append(*mi);//insert(*mi,positionOfLastDialog++);
 
-    mi = Gtk::manage(new Gtk::MenuItem(_("Unhide objects below"),1));
+    mi = Gtk::manage(new Gtk::MenuItem(_("Unhide objects below"),true));
     mi->signal_activate().connect(sigc::bind<std::vector< SPItem * > >(sigc::mem_fun(*this, &ContextMenu::UnHideBelow), down_items));
     if (!has_down_hidden) {
         mi->set_sensitive(false);
@@ -110,7 +110,7 @@ ContextMenu::ContextMenu(SPDesktop *desktop, SPItem *item) :
     mi->show();
     append(*mi);//insert(*mi,positionOfLastDialog++);
 
-    mi = Gtk::manage(new Gtk::MenuItem(_("Lock selected objects"),1));
+    mi = Gtk::manage(new Gtk::MenuItem(_("Lock selected objects"),true));
     mi->signal_activate().connect(sigc::mem_fun(*this, &ContextMenu::LockSelected));
     if (_desktop->selection->isEmpty()) {
         mi->set_sensitive(false);
@@ -118,7 +118,7 @@ ContextMenu::ContextMenu(SPDesktop *desktop, SPItem *item) :
     mi->show();
     append(*mi);//insert(*mi,positionOfLastDialog++);
 
-    mi = Gtk::manage(new Gtk::MenuItem(_("Unlock objects below"),1));
+    mi = Gtk::manage(new Gtk::MenuItem(_("Unlock objects below"),true));
     mi->signal_activate().connect(sigc::bind<std::vector< SPItem * > >(sigc::mem_fun(*this, &ContextMenu::UnLockBelow), down_items));
     if (!has_down_locked) {
         mi->set_sensitive(false);
@@ -156,7 +156,7 @@ ContextMenu::ContextMenu(SPDesktop *desktop, SPItem *item) :
             append(MIParent);
 
             /* Pop selection out of group */
-            Gtk::MenuItem* miu = Gtk::manage(new Gtk::MenuItem(_("_Pop selection out of group"), 1));
+            Gtk::MenuItem* miu = Gtk::manage(new Gtk::MenuItem(_("_Pop selection out of group"), true));
             miu->signal_activate().connect(sigc::mem_fun(*this, &ContextMenu::ActivateUngroupPopSelection));
             miu->show();
             append(*miu);
@@ -320,7 +320,7 @@ void ContextMenu::MakeItemMenu (void)
     Gtk::MenuItem* mi;
 
     /* Item dialog */
-    mi = Gtk::manage(new Gtk::MenuItem(_("_Object Properties..."),1));
+    mi = Gtk::manage(new Gtk::MenuItem(_("_Object Properties..."),true));
     mi->signal_activate().connect(sigc::mem_fun(*this, &ContextMenu::ItemProperties));
     mi->show();
     append(*mi);//insert(*mi,positionOfLastDialog++);
@@ -329,7 +329,7 @@ void ContextMenu::MakeItemMenu (void)
     
     /* Select item */
     if (Inkscape::Verb::getbyid( "org.inkscape.followlink" )) {
-        mi = Gtk::manage(new Gtk::MenuItem(_("_Select This"), 1));
+        mi = Gtk::manage(new Gtk::MenuItem(_("_Select This"), true));
         if (_desktop->selection->includes(_item)) {
             mi->set_sensitive(FALSE);
         } else {
@@ -350,42 +350,42 @@ void ContextMenu::MakeItemMenu (void)
     append(*mi);
 
     /* Select same fill and stroke */
-    mi = Gtk::manage(new Gtk::MenuItem(_("Fill and Stroke"), 1));
+    mi = Gtk::manage(new Gtk::MenuItem(_("Fill and Stroke"), true));
     mi->signal_activate().connect(sigc::mem_fun(*this, &ContextMenu::SelectSameFillStroke));
     mi->set_sensitive(!SP_IS_ANCHOR(_item));
     mi->show();
     select_same_submenu->append(*mi);
 
     /* Select same fill color */
-    mi = Gtk::manage(new Gtk::MenuItem(_("Fill Color"), 1));
+    mi = Gtk::manage(new Gtk::MenuItem(_("Fill Color"), true));
     mi->signal_activate().connect(sigc::mem_fun(*this, &ContextMenu::SelectSameFillColor));
     mi->set_sensitive(!SP_IS_ANCHOR(_item));
     mi->show();
     select_same_submenu->append(*mi);
 
     /* Select same stroke color */
-    mi = Gtk::manage(new Gtk::MenuItem(_("Stroke Color"), 1));
+    mi = Gtk::manage(new Gtk::MenuItem(_("Stroke Color"), true));
     mi->signal_activate().connect(sigc::mem_fun(*this, &ContextMenu::SelectSameStrokeColor));
     mi->set_sensitive(!SP_IS_ANCHOR(_item));
     mi->show();
     select_same_submenu->append(*mi);
 
     /* Select same stroke style */
-    mi = Gtk::manage(new Gtk::MenuItem(_("Stroke Style"), 1));
+    mi = Gtk::manage(new Gtk::MenuItem(_("Stroke Style"), true));
     mi->signal_activate().connect(sigc::mem_fun(*this, &ContextMenu::SelectSameStrokeStyle));
     mi->set_sensitive(!SP_IS_ANCHOR(_item));
     mi->show();
     select_same_submenu->append(*mi);
 
     /* Select same stroke style */
-    mi = Gtk::manage(new Gtk::MenuItem(_("Object type"), 1));
+    mi = Gtk::manage(new Gtk::MenuItem(_("Object type"), true));
     mi->signal_activate().connect(sigc::mem_fun(*this, &ContextMenu::SelectSameObjectType));
     mi->set_sensitive(!SP_IS_ANCHOR(_item));
     mi->show();
     select_same_submenu->append(*mi);
 
     /* Move to layer */
-    mi = Gtk::manage(new Gtk::MenuItem(_("_Move to layer ..."), 1));
+    mi = Gtk::manage(new Gtk::MenuItem(_("_Move to layer ..."), true));
     if (_desktop->selection->isEmpty()) {
         mi->set_sensitive(FALSE);
     } else {
@@ -395,7 +395,7 @@ void ContextMenu::MakeItemMenu (void)
     append(*mi);
 
     /* Create link */
-    mi = Gtk::manage(new Gtk::MenuItem(_("Create _Link"), 1));
+    mi = Gtk::manage(new Gtk::MenuItem(_("Create _Link"), true));
     mi->signal_activate().connect(sigc::mem_fun(*this, &ContextMenu::ItemCreateLink));
     mi->set_sensitive(!SP_IS_ANCHOR(_item));
     mi->show();
@@ -418,7 +418,7 @@ void ContextMenu::MakeItemMenu (void)
         }
     }    
     /* Set mask */
-    mi = Gtk::manage(new Gtk::MenuItem(_("Set Mask"), 1));
+    mi = Gtk::manage(new Gtk::MenuItem(_("Set Mask"), true));
     mi->signal_activate().connect(sigc::mem_fun(*this, &ContextMenu::SetMask));
     if (ClipRefOK || MaskRefOK) {
         mi->set_sensitive(FALSE);
@@ -429,7 +429,7 @@ void ContextMenu::MakeItemMenu (void)
     append(*mi);
     
     /* Release mask */
-    mi = Gtk::manage(new Gtk::MenuItem(_("Release Mask"), 1));
+    mi = Gtk::manage(new Gtk::MenuItem(_("Release Mask"), true));
     mi->signal_activate().connect(sigc::mem_fun(*this, &ContextMenu::ReleaseMask));
     if (MaskRefOK) {
         mi->set_sensitive(TRUE);
@@ -440,14 +440,14 @@ void ContextMenu::MakeItemMenu (void)
     append(*mi);
 
     /*SSet Clip Group */
-    mi = Gtk::manage(new Gtk::MenuItem(_("Create Clip G_roup"),1));
+    mi = Gtk::manage(new Gtk::MenuItem(_("Create Clip G_roup"),true));
     mi->signal_activate().connect(sigc::mem_fun(*this, &ContextMenu::CreateGroupClip));
     mi->set_sensitive(TRUE);
     mi->show();
     append(*mi);
     
     /* Set Clip */
-    mi = Gtk::manage(new Gtk::MenuItem(_("Set Cl_ip"), 1));
+    mi = Gtk::manage(new Gtk::MenuItem(_("Set Cl_ip"), true));
     mi->signal_activate().connect(sigc::mem_fun(*this, &ContextMenu::SetClip));
     if (ClipRefOK || MaskRefOK) {
         mi->set_sensitive(FALSE);
@@ -458,7 +458,7 @@ void ContextMenu::MakeItemMenu (void)
     append(*mi);
     
     /* Release Clip */
-    mi = Gtk::manage(new Gtk::MenuItem(_("Release C_lip"), 1));
+    mi = Gtk::manage(new Gtk::MenuItem(_("Release C_lip"), true));
     mi->signal_activate().connect(sigc::mem_fun(*this, &ContextMenu::ReleaseClip));
     if (ClipRefOK) {
         mi->set_sensitive(TRUE);
@@ -469,7 +469,7 @@ void ContextMenu::MakeItemMenu (void)
     append(*mi);
 
     /* Group */
-    mi = Gtk::manage(new Gtk::MenuItem(_("_Group"), 1));
+    mi = Gtk::manage(new Gtk::MenuItem(_("_Group"), true));
     mi->signal_activate().connect(sigc::mem_fun(*this, &ContextMenu::ActivateGroup));
     if (_desktop->selection->isEmpty()) {
         mi->set_sensitive(FALSE);
@@ -575,7 +575,7 @@ void ContextMenu::ReleaseClip(void)
 void ContextMenu::MakeGroupMenu(void)
 {
     /* Ungroup */
-    Gtk::MenuItem* mi = Gtk::manage(new Gtk::MenuItem(_("_Ungroup"), 1));
+    Gtk::MenuItem* mi = Gtk::manage(new Gtk::MenuItem(_("_Ungroup"), true));
     mi->signal_activate().connect(sigc::mem_fun(*this, &ContextMenu::ActivateUngroup));
     mi->show();
     append(*mi);
@@ -605,19 +605,19 @@ void ContextMenu::MakeAnchorMenu(void)
     Gtk::MenuItem* mi;
     
     /* Link dialog */
-    mi = Gtk::manage(new Gtk::MenuItem(_("Link _Properties..."), 1));
+    mi = Gtk::manage(new Gtk::MenuItem(_("Link _Properties..."), true));
     mi->signal_activate().connect(sigc::mem_fun(*this, &ContextMenu::AnchorLinkProperties));
     mi->show();
     insert(*mi,positionOfLastDialog++);
     
     /* Select item */
-    mi = Gtk::manage(new Gtk::MenuItem(_("_Follow Link"), 1));
+    mi = Gtk::manage(new Gtk::MenuItem(_("_Follow Link"), true));
     mi->signal_activate().connect(sigc::mem_fun(*this, &ContextMenu::AnchorLinkFollow));
     mi->show();
     append(*mi);
     
     /* Reset transformations */
-    mi = Gtk::manage(new Gtk::MenuItem(_("_Remove Link"), 1));
+    mi = Gtk::manage(new Gtk::MenuItem(_("_Remove Link"), true));
     mi->signal_activate().connect(sigc::mem_fun(*this, &ContextMenu::AnchorLinkRemove));
     mi->show();
     append(*mi);
@@ -658,13 +658,13 @@ void ContextMenu::MakeImageMenu (void)
     const gchar *href = ir->attribute("xlink:href");
 
     /* Image properties */
-    mi = Gtk::manage(new Gtk::MenuItem(_("Image _Properties..."), 1));
+    mi = Gtk::manage(new Gtk::MenuItem(_("Image _Properties..."), true));
     mi->signal_activate().connect(sigc::mem_fun(*this, &ContextMenu::ImageProperties));
     mi->show();
     insert(*mi,positionOfLastDialog++);
 
     /* Edit externally */
-    mi = Gtk::manage(new Gtk::MenuItem(_("Edit Externally..."), 1));
+    mi = Gtk::manage(new Gtk::MenuItem(_("Edit Externally..."), true));
     mi->signal_activate().connect(sigc::mem_fun(*this, &ContextMenu::ImageEdit));
     mi->show();
     insert(*mi,positionOfLastDialog++);
@@ -673,7 +673,7 @@ void ContextMenu::MakeImageMenu (void)
     }
 
     /* Trace Bitmap */
-    mi = Gtk::manage(new Gtk::MenuItem(_("_Trace Bitmap..."), 1));
+    mi = Gtk::manage(new Gtk::MenuItem(_("_Trace Bitmap..."), true));
     mi->signal_activate().connect(sigc::mem_fun(*this, &ContextMenu::ImageTraceBitmap));
     mi->show();
     insert(*mi,positionOfLastDialog++);
@@ -682,7 +682,7 @@ void ContextMenu::MakeImageMenu (void)
     }
 
     /* Trace Pixel Art */
-    mi = Gtk::manage(new Gtk::MenuItem(_("Trace Pixel Art"), 1));
+    mi = Gtk::manage(new Gtk::MenuItem(_("Trace Pixel Art"), true));
     mi->signal_activate().connect(sigc::mem_fun(*this, &ContextMenu::ImageTracePixelArt));
     mi->show();
     insert(*mi,positionOfLastDialog++);
@@ -864,7 +864,7 @@ void ContextMenu::MakeShapeMenu (void)
     Gtk::MenuItem* mi;
     
     /* Item dialog */
-    mi = Gtk::manage(new Gtk::MenuItem(_("_Fill and Stroke..."), 1));
+    mi = Gtk::manage(new Gtk::MenuItem(_("_Fill and Stroke..."), true));
     mi->signal_activate().connect(sigc::mem_fun(*this, &ContextMenu::FillSettings));
     mi->show();
     insert(*mi,positionOfLastDialog++);
@@ -884,19 +884,19 @@ void ContextMenu::MakeTextMenu (void)
     Gtk::MenuItem* mi;
 
     /* Fill and Stroke dialog */
-    mi = Gtk::manage(new Gtk::MenuItem(_("_Fill and Stroke..."), 1));
+    mi = Gtk::manage(new Gtk::MenuItem(_("_Fill and Stroke..."), true));
     mi->signal_activate().connect(sigc::mem_fun(*this, &ContextMenu::FillSettings));
     mi->show();
     insert(*mi,positionOfLastDialog++);
     
     /* Edit Text dialog */
-    mi = Gtk::manage(new Gtk::MenuItem(_("_Text and Font..."), 1));
+    mi = Gtk::manage(new Gtk::MenuItem(_("_Text and Font..."), true));
     mi->signal_activate().connect(sigc::mem_fun(*this, &ContextMenu::TextSettings));
     mi->show();
     insert(*mi,positionOfLastDialog++);
 
     /* Spellcheck dialog */
-    mi = Gtk::manage(new Gtk::MenuItem(_("Check Spellin_g..."), 1));
+    mi = Gtk::manage(new Gtk::MenuItem(_("Check Spellin_g..."), true));
     mi->signal_activate().connect(sigc::mem_fun(*this, &ContextMenu::SpellcheckSettings));
     mi->show();
     insert(*mi,positionOfLastDialog++);
diff --git a/src/ui/dialog/align-and-distribute.cpp b/src/ui/dialog/align-and-distribute.cpp
index ad69bb59c..8e6b5e0e5 100644
--- a/src/ui/dialog/align-and-distribute.cpp
+++ b/src/ui/dialog/align-and-distribute.cpp
@@ -936,7 +936,7 @@ AlignAndDistribute::AlignAndDistribute()
       _nodesTable(),
       _anchorLabel(_("Relative to: ")),
       _anchorLabelNode(_("Relative to: ")),
-      _selgrpLabel(_("_Treat selection as group: "), 1)
+      _selgrpLabel(_("_Treat selection as group: "), true)
 {
     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 
diff --git a/src/ui/dialog/clonetiler.cpp b/src/ui/dialog/clonetiler.cpp
index c1998249d..3346dd595 100644
--- a/src/ui/dialog/clonetiler.cpp
+++ b/src/ui/dialog/clonetiler.cpp
@@ -919,7 +919,7 @@ CloneTiler::CloneTiler () :
 
                 {
                     auto b = Gtk::manage(new Gtk::CheckButton(_("Color")));
-                    bool old = prefs->getBool(prefs_path + "pick_to_color", 0);
+                    bool old = prefs->getBool(prefs_path + "pick_to_color", false);
                     b->set_active(old);
                     b->set_tooltip_text(_("Each clone is painted by the picked color (the original must have unset fill or stroke)"));
                     table_attach (table, b, 0.0, 1, 2);
@@ -928,7 +928,7 @@ CloneTiler::CloneTiler () :
 
                 {
                     auto b = Gtk::manage(new Gtk::CheckButton(_("Opacity")));
-                    bool old = prefs->getBool(prefs_path + "pick_to_opacity", 0);
+                    bool old = prefs->getBool(prefs_path + "pick_to_opacity", false);
                     b->set_active(old);
                     b->set_tooltip_text(_("Each clone's opacity is determined by the picked value in that point"));
                     table_attach (table, b, 0.0, 2, 2);
diff --git a/src/ui/dialog/document-properties.cpp b/src/ui/dialog/document-properties.cpp
index 1dda7f17d..0b47f9bac 100644
--- a/src/ui/dialog/document-properties.cpp
+++ b/src/ui/dialog/document-properties.cpp
@@ -1024,9 +1024,9 @@ void DocumentProperties::build_metadata()
         }
     }
 
-    Gtk::Button *button_save = Gtk::manage (new Gtk::Button(_("_Save as default"),1));
+    Gtk::Button *button_save = Gtk::manage (new Gtk::Button(_("_Save as default"),true));
     button_save->set_tooltip_text(_("Save this metadata as the default metadata"));
-    Gtk::Button *button_load = Gtk::manage (new Gtk::Button(_("Use _default"),1));
+    Gtk::Button *button_load = Gtk::manage (new Gtk::Button(_("Use _default"),true));
     button_load->set_tooltip_text(_("Use the previously saved default metadata here"));
 
     auto box_buttons = Gtk::manage (new Gtk::ButtonBox);
diff --git a/src/ui/dialog/export.cpp b/src/ui/dialog/export.cpp
index 4d61091a2..392587bef 100644
--- a/src/ui/dialog/export.cpp
+++ b/src/ui/dialog/export.cpp
@@ -138,7 +138,7 @@ Export::Export (void) :
     unit_selector(),
     units_label(_("Units:")),
     filename_box(false, 5),
-    browse_label(_("_Export As..."), 1),
+    browse_label(_("_Export As..."), true),
     browse_image(),
     batch_box(false, 5),
     batch_export(_("B_atch export all selected objects"), _("Export each selected object into its own PNG file, using export hints if any (caution, overwrites without asking!)")),
@@ -324,7 +324,7 @@ Export::Export (void) :
     button_box.pack_end(export_button, false, false, 0);
 
     /*Advanced*/
-    Gtk::Label *label_advanced = Gtk::manage(new Gtk::Label(_("Advanced"),1));
+    Gtk::Label *label_advanced = Gtk::manage(new Gtk::Label(_("Advanced"),true));
     expander.set_label_widget(*label_advanced);
     const char* const modes_list[]={"Gray_1", "Gray_2","Gray_4","Gray_8","Gray_16","RGB_8","RGB_16","GrayAlpha_8","GrayAlpha_16","RGBA_8","RGBA_16"};
     for(int i=0; i<11; ++i)
@@ -363,7 +363,7 @@ Export::Export (void) :
     contents->pack_start(singleexport_box);
     contents->pack_start(batch_box);
     contents->pack_start(hide_box);
-    contents->pack_end(button_box, false, 0);
+    contents->pack_end(button_box, false, false);
     contents->pack_end(_prog, Gtk::PACK_EXPAND_WIDGET);
     contents->pack_end(expander, FALSE, FALSE,0);
 
diff --git a/src/ui/dialog/filedialogimpl-gtkmm.cpp b/src/ui/dialog/filedialogimpl-gtkmm.cpp
index 006a59ece..72cca76d3 100644
--- a/src/ui/dialog/filedialogimpl-gtkmm.cpp
+++ b/src/ui/dialog/filedialogimpl-gtkmm.cpp
@@ -1076,7 +1076,7 @@ void FileSaveDialogImplGtk::fileNameEntryChangedCallback()
 
     if (Glib::file_test(fileName, Glib::FILE_TEST_IS_DIR)) {
         set_current_folder(fileName);
-    } else if (/*Glib::file_test(fileName, Glib::FILE_TEST_IS_REGULAR)*/ 1) {
+    } else if (/*Glib::file_test(fileName, Glib::FILE_TEST_IS_REGULAR)*/ true) {
         // dialog with either (1) select a regular file or (2) cd to dir
         // simulate an 'OK'
         set_filename(fileName);
diff --git a/src/ui/dialog/find.cpp b/src/ui/dialog/find.cpp
index a010ac667..d9a43d21b 100644
--- a/src/ui/dialog/find.cpp
+++ b/src/ui/dialog/find.cpp
@@ -71,7 +71,7 @@ Find::Find()
       check_scope_selection(_("Sele_ction"), _("Limit search to the current selection")),
       check_searchin_text(_("_Text"), _("Search in text objects")),
       check_searchin_property(_("_Properties"), _("Search in object properties, styles, attributes and IDs")),
-      vbox_searchin(0, false),
+      vbox_searchin(false, false),
       frame_searchin(_("Search in")),
       frame_scope(_("Scope")),
 
diff --git a/src/ui/dialog/inkscape-preferences.cpp b/src/ui/dialog/inkscape-preferences.cpp
index 06309885c..6092c26d3 100644
--- a/src/ui/dialog/inkscape-preferences.cpp
+++ b/src/ui/dialog/inkscape-preferences.cpp
@@ -493,7 +493,7 @@ void InkscapePreferences::initPageTools()
     this->AddGradientCheckbox(_page_text, "/tools/text", true);
     {
         PrefCheckButton* cb = Gtk::manage( new PrefCheckButton);
-        cb->init ( _("Show font samples in the drop-down list"), "/tools/text/show_sample_in_list", 1);
+        cb->init ( _("Show font samples in the drop-down list"), "/tools/text/show_sample_in_list", true);
         _page_text.add_line( false, "", *cb, "", _("Show font samples alongside font names in the drop-down list in Text bar"));
 
         _font_dialog.init ( _("Show font substitution warning dialog"), "/options/font/substitutedlg", false);
diff --git a/src/ui/dialog/object-properties.cpp b/src/ui/dialog/object-properties.cpp
index a43791d08..8f92050f5 100644
--- a/src/ui/dialog/object-properties.cpp
+++ b/src/ui/dialog/object-properties.cpp
@@ -50,12 +50,12 @@ ObjectProperties::ObjectProperties()
     : UI::Widget::Panel("/dialogs/object/", SP_VERB_DIALOG_ITEM)
     , _blocked (false)
     , _current_item(nullptr)
-    , _label_id(_("_ID:"), 1)
-    , _label_label(_("_Label:"), 1)
-    , _label_title(_("_Title:"), 1)
-    , _label_image_rendering(_("_Image Rendering:"), 1)
-    , _cb_hide(_("_Hide"), 1)
-    , _cb_lock(_("L_ock"), 1)
+    , _label_id(_("_ID:"), true)
+    , _label_label(_("_Label:"), true)
+    , _label_title(_("_Title:"), true)
+    , _label_image_rendering(_("_Image Rendering:"), true)
+    , _cb_hide(_("_Hide"), true)
+    , _cb_lock(_("L_ock"), true)
     , _attr_table(Gtk::manage(new SPAttributeTable()))
     , _desktop(nullptr)
 {
@@ -168,7 +168,7 @@ void ObjectProperties::_init()
     _entry_title.signal_activate().connect(sigc::mem_fun(this, &ObjectProperties::_labelChanged));
 
     /* Create the frame for the object description */
-    Gtk::Label *label_desc = Gtk::manage(new Gtk::Label(_("_Description:"), 1));
+    Gtk::Label *label_desc = Gtk::manage(new Gtk::Label(_("_Description:"), true));
     UI::Widget::Frame *frame_desc = Gtk::manage(new UI::Widget::Frame("", FALSE));
     frame_desc->set_label_widget(*label_desc);
     frame_desc->set_padding (0,0,0,0);
@@ -237,7 +237,7 @@ void ObjectProperties::_init()
 
 
     /* Button for setting the object's id, label, title and description. */
-    Gtk::Button *btn_set = Gtk::manage(new Gtk::Button(_("_Set"), 1));
+    Gtk::Button *btn_set = Gtk::manage(new Gtk::Button(_("_Set"), true));
     btn_set->set_hexpand();
     btn_set->set_valign(Gtk::ALIGN_CENTER);
     grid_cb->attach(*btn_set, 2, 0, 1, 1);
@@ -245,7 +245,7 @@ void ObjectProperties::_init()
     btn_set->signal_clicked().connect(sigc::mem_fun(this, &ObjectProperties::_labelChanged));
 
     /* Create the frame for interactivity options */
-    Gtk::Label *label_interactivity = Gtk::manage(new Gtk::Label(_("_Interactivity"), 1));
+    Gtk::Label *label_interactivity = Gtk::manage(new Gtk::Label(_("_Interactivity"), true));
     _exp_interactivity.set_label_widget(*label_interactivity);
     contents->pack_start(_exp_interactivity, FALSE, FALSE, 0);
 
diff --git a/src/ui/dialog/swatches.cpp b/src/ui/dialog/swatches.cpp
index 7d8729b0e..dbb170025 100644
--- a/src/ui/dialog/swatches.cpp
+++ b/src/ui/dialog/swatches.cpp
@@ -693,7 +693,7 @@ SwatchesPanel::~SwatchesPanel()
 void SwatchesPanel::_build_menu()
 {
     guint panel_size = 0, panel_mode = 0, panel_ratio = 100, panel_border = 0;
-    bool panel_wrap = 0;
+    bool panel_wrap = false;
     if (!_prefs_path.empty()) {
         Inkscape::Preferences *prefs = Inkscape::Preferences::get();
         panel_wrap = prefs->getBool(_prefs_path + "/panel_wrap");
diff --git a/src/ui/dialog/symbols.cpp b/src/ui/dialog/symbols.cpp
index af044eff0..a4d067acd 100644
--- a/src/ui/dialog/symbols.cpp
+++ b/src/ui/dialog/symbols.cpp
@@ -106,7 +106,7 @@ SymbolColumns* SymbolsDialog::getColumns()
 SymbolsDialog::SymbolsDialog( gchar const* prefsPath ) :
   UI::Widget::Panel(prefsPath, SP_VERB_DIALOG_SYMBOLS),
   store(Gtk::ListStore::create(*getColumns())),
-  all_docs_processed(0),
+  all_docs_processed(false),
   icon_view(nullptr),
   current_desktop(nullptr),
   desk_track(),
diff --git a/src/ui/tool/multi-path-manipulator.cpp b/src/ui/tool/multi-path-manipulator.cpp
index 7010f58bf..b80a1e675 100644
--- a/src/ui/tool/multi-path-manipulator.cpp
+++ b/src/ui/tool/multi-path-manipulator.cpp
@@ -616,7 +616,7 @@ bool MultiPathManipulator::event(Inkscape::UI::Tools::ToolBase *event_context, G
             }
 
             if (handled) return true;
-        } while(0);
+        } while(false);
     }
 
 
diff --git a/src/ui/tools/connector-tool.cpp b/src/ui/tools/connector-tool.cpp
index 7481e8470..09f18e630 100644
--- a/src/ui/tools/connector-tool.cpp
+++ b/src/ui/tools/connector-tool.cpp
@@ -242,7 +242,7 @@ void ConnectorTool::setup()
     sp_event_context_read(this, "curvature");
     sp_event_context_read(this, "orthogonal");
     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
-    if (prefs->getBool("/tools/connector/selcue", 0)) {
+    if (prefs->getBool("/tools/connector/selcue", false)) {
         this->enableSelectionCue();
     }
 
diff --git a/src/ui/tools/eraser-tool.cpp b/src/ui/tools/eraser-tool.cpp
index 1cd9db6b2..60d572e16 100644
--- a/src/ui/tools/eraser-tool.cpp
+++ b/src/ui/tools/eraser-tool.cpp
@@ -151,7 +151,7 @@ static ProfileFloatElement f_profile[PROFILE_FLOAT_SIZE] = {
     //TODO not sure why get 0.01 if slider width == 0, maybe a double/int problem
 
     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
-    if (prefs->getBool("/tools/eraser/selcue", 0) != 0) {
+    if (prefs->getBool("/tools/eraser/selcue", false) != 0) {
     	this->enableSelectionCue();
     }
 
diff --git a/src/ui/tools/measure-tool.cpp b/src/ui/tools/measure-tool.cpp
index 633bf6ec3..2048dce23 100644
--- a/src/ui/tools/measure-tool.cpp
+++ b/src/ui/tools/measure-tool.cpp
@@ -1177,7 +1177,7 @@ void MeasureTool::showInfoBox(Geom::Point cursor, bool into_groups)
         if(newover != over){
             over = newover;
             Preferences *prefs = Preferences::get();
-            int prefs_bbox = prefs->getBool("/tools/bounding_box", 0);
+            int prefs_bbox = prefs->getBool("/tools/bounding_box", false);
             SPItem::BBoxType bbox_type = !prefs_bbox ? SPItem::VISUAL_BBOX : SPItem::GEOMETRIC_BBOX;
             Geom::OptRect bbox = over->bounds(bbox_type);
             if (bbox) {
diff --git a/src/ui/tools/pen-tool.cpp b/src/ui/tools/pen-tool.cpp
index c5855540b..e7301152f 100644
--- a/src/ui/tools/pen-tool.cpp
+++ b/src/ui/tools/pen-tool.cpp
@@ -1291,7 +1291,7 @@ void PenTool::_setAngleDistanceStatusMessage(Geom::Point const p, int pc_point_t
     Glib::ustring dist = q.string(desktop->namedview->display_units);
     double angle = atan2(rel[Geom::Y], rel[Geom::X]) * 180 / M_PI;
     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
-    if (prefs->getBool("/options/compassangledisplay/value", 0) != 0) {
+    if (prefs->getBool("/options/compassangledisplay/value", false) != 0) {
         angle = 90 - angle;
         if (angle < 0) {
             angle += 360;
diff --git a/src/ui/tools/text-tool.cpp b/src/ui/tools/text-tool.cpp
index f4f20ef30..8ed03ece1 100644
--- a/src/ui/tools/text-tool.cpp
+++ b/src/ui/tools/text-tool.cpp
@@ -452,7 +452,7 @@ static void insert_uni_char(TextTool *const tc)
     } else {
         if (!tc->text) { // printable key; create text if none (i.e. if nascent_object)
             sp_text_context_setup_text(tc);
-            tc->nascent_object = 0; // we don't need it anymore, having created a real <text>
+            tc->nascent_object = false; // we don't need it anymore, having created a real <text>
         }
 
         gchar u[10];
@@ -539,7 +539,7 @@ bool TextTool::root_handler(GdkEvent* event) {
                                     GDK_KEY_PRESS_MASK | GDK_BUTTON_RELEASE_MASK | GDK_BUTTON_PRESS_MASK | GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK,
                                     nullptr, event->button.time);
                 this->grabbed = SP_CANVAS_ITEM(desktop->acetate);
-                this->creating = 1;
+                this->creating = true;
 
                 /* Processed */
                 return TRUE;
@@ -547,7 +547,7 @@ bool TextTool::root_handler(GdkEvent* event) {
             break;
         case GDK_MOTION_NOTIFY:
             if (this->over_text) {
-                this->over_text = 0;
+                this->over_text = false;
                 // update cursor and statusbar: we are not over a text object now
                 this->cursor_shape = cursor_text_xpm;
                 this->sp_event_context_update_cursor();
@@ -615,8 +615,8 @@ bool TextTool::root_handler(GdkEvent* event) {
                     desktop->getSelection()->clear();
                     this->pdoc = desktop->dt2doc(p1);
                     this->show = TRUE;
-                    this->phase = 1;
-                    this->nascent_object = 1; // new object was just created
+                    this->phase = true;
+                    this->nascent_object = true; // new object was just created
 
                     /* Cursor */
                     sp_canvas_item_show(this->cursor);
@@ -780,7 +780,7 @@ bool TextTool::root_handler(GdkEvent* event) {
                                     /* No-break space */
                                     if (!this->text) { // printable key; create text if none (i.e. if nascent_object)
                                         sp_text_context_setup_text(this);
-                                        this->nascent_object = 0; // we don't need it anymore, having created a real <text>
+                                        this->nascent_object = false; // we don't need it anymore, having created a real <text>
                                     }
                                     this->text_sel_start = this->text_sel_end = sp_te_replace(this->text, this->text_sel_start, this->text_sel_end, "\302\240");
                                     sp_text_context_update_cursor(this);
@@ -865,7 +865,7 @@ bool TextTool::root_handler(GdkEvent* event) {
                             {
                                 if (!this->text) { // printable key; create text if none (i.e. if nascent_object)
                                     sp_text_context_setup_text(this);
-                                    this->nascent_object = 0; // we don't need it anymore, having created a real <text>
+                                    this->nascent_object = false; // we don't need it anymore, having created a real <text>
                                 }
 
                                 iterator_pair enter_pair;
@@ -1095,7 +1095,7 @@ bool TextTool::root_handler(GdkEvent* event) {
                                 return TRUE;
                             case GDK_KEY_Escape:
                                 if (this->creating) {
-                                    this->creating = 0;
+                                    this->creating = false;
                                     if (this->grabbed) {
                                         sp_canvas_item_ungrab(this->grabbed, GDK_CURRENT_TIME);
                                         this->grabbed = nullptr;
@@ -1217,7 +1217,7 @@ bool TextTool::root_handler(GdkEvent* event) {
                     return TRUE;
                 } else if (group0_keyval == GDK_KEY_Escape) { // cancel rubberband
                     if (this->creating) {
-                        this->creating = 0;
+                        this->creating = false;
                         if (this->grabbed) {
                             sp_canvas_item_ungrab(this->grabbed, GDK_CURRENT_TIME);
                             this->grabbed = nullptr;
@@ -1297,7 +1297,7 @@ bool sp_text_paste_inline(ToolBase *ec)
 
             if (!tc->text) { // create text if none (i.e. if nascent_object)
                 sp_text_context_setup_text(tc);
-                tc->nascent_object = 0; // we don't need it anymore, having created a real <text>
+                tc->nascent_object = false; // we don't need it anymore, having created a real <text>
             }
 
             // using indices is slow in ustrings. Whatever.
@@ -1591,7 +1591,7 @@ static void sp_text_context_update_cursor(TextTool *tc,  bool scroll_to_see)
         }
 
         tc->show = TRUE;
-        tc->phase = 1;
+        tc->phase = true;
 
         Inkscape::Text::Layout const *layout = te_get_layout(tc->text);
         int const nChars = layout->iteratorToCharIndex(layout->end());
@@ -1665,10 +1665,10 @@ static gint sp_text_context_timeout(TextTool *tc)
     if (tc->show) {
         sp_canvas_item_show(tc->cursor);
         if (tc->phase) {
-            tc->phase = 0;
+            tc->phase = false;
             tc->cursor->setRgba32(0x000000ff);
         } else {
-            tc->phase = 1;
+            tc->phase = true;
             tc->cursor->setRgba32(0xffffffff);
         }
     }
@@ -1720,7 +1720,7 @@ static void sptc_commit(GtkIMContext */*imc*/, gchar *string, TextTool *tc)
 {
     if (!tc->text) {
         sp_text_context_setup_text(tc);
-        tc->nascent_object = 0; // we don't need it anymore, having created a real <text>
+        tc->nascent_object = false; // we don't need it anymore, having created a real <text>
     }
 
     tc->text_sel_start = tc->text_sel_end = sp_te_replace(tc->text, tc->text_sel_start, tc->text_sel_end, string);
diff --git a/src/widgets/button.cpp b/src/widgets/button.cpp
index 7ebc20b6f..19443716c 100644
--- a/src/widgets/button.cpp
+++ b/src/widgets/button.cpp
@@ -227,7 +227,7 @@ static void sp_button_action_set_active(SPButton *button, bool active)
     }
 
     /* temporarily lobotomized until SPActions are per-view */
-    if (0 && !active != !SP_BUTTON_IS_DOWN(button)) {
+    if (false && !active != !SP_BUTTON_IS_DOWN(button)) {
         sp_button_toggle_set_down(button, active);
     }
 }