Support percentage (include default) values for linear and radial gradient attribues.

Fix for inbox issue #415.

4 files changed, 86 insertions, 11 deletions

diff --git a/src/object/sp-linear-gradient.cpp b/src/object/sp-linear-gradient.cpp
index 4d2867f98..7b0029356 100644
--- a/src/object/sp-linear-gradient.cpp
+++ b/src/object/sp-linear-gradient.cpp
@@ -12,6 +12,7 @@
 #include "sp-linear-gradient.h"
 
 #include "attributes.h"
+#include "style.h"
 #include "xml/repr.h"
 
 /*
@@ -66,6 +67,29 @@ void SPLinearGradient::set(SPAttributeEnum key, const gchar* value) {
     }
 }
 
+void
+SPLinearGradient::update(SPCtx *ctx, guint flags)
+{
+    // To do: Verify flags.
+    if (flags & (SP_OBJECT_MODIFIED_FLAG | SP_OBJECT_STYLE_MODIFIED_FLAG | SP_OBJECT_VIEWPORT_MODIFIED_FLAG)) {
+
+        SPItemCtx const *ictx = reinterpret_cast<SPItemCtx const *>(ctx);
+
+        if (getUnits() == SP_GRADIENT_UNITS_USERSPACEONUSE) {
+            double w = ictx->viewport.width();
+            double h = ictx->viewport.height();
+            double d = sqrt ((w*w + h*h)/2.0);
+            double const em = style->font_size.computed;
+            double const ex = 0.5 * em;  // fixme: get x height from pango or libnrtype.
+
+            this->x1.update(em, ex, w);
+            this->y1.update(em, ex, h);
+            this->x2.update(em, ex, w);
+            this->y2.update(em, ex, h);
+        }
+    }
+}
+
 /**
  * Callback: write attributes to associated repr.
  */
@@ -106,3 +130,14 @@ cairo_pattern_t* SPLinearGradient::pattern_new(cairo_t * /*ct*/, Geom::OptRect c
 
     return cp;
 }
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/object/sp-linear-gradient.h b/src/object/sp-linear-gradient.h
index f88c38dc4..c54e900c2 100644
--- a/src/object/sp-linear-gradient.h
+++ b/src/object/sp-linear-gradient.h
@@ -23,20 +23,21 @@
 /** Linear gradient. */
 class SPLinearGradient : public SPGradient {
 public:
-	SPLinearGradient();
-	~SPLinearGradient() override;
+    SPLinearGradient();
+    ~SPLinearGradient() override;
 
     SVGLength x1;
     SVGLength y1;
     SVGLength x2;
     SVGLength y2;
 
-	cairo_pattern_t* pattern_new(cairo_t *ct, Geom::OptRect const &bbox, double opacity) override;
+    cairo_pattern_t* pattern_new(cairo_t *ct, Geom::OptRect const &bbox, double opacity) override;
 
 protected:
-	void build(SPDocument *document, Inkscape::XML::Node *repr) override;
-	void set(SPAttributeEnum key, char const *value) override;
-	Inkscape::XML::Node* write(Inkscape::XML::Document *xml_doc, Inkscape::XML::Node *repr, unsigned int flags) override;
+    void build(SPDocument *document, Inkscape::XML::Node *repr) override;
+    void set(SPAttributeEnum key, char const *value) override;
+    void update(SPCtx *ctx, guint flags) override;
+    Inkscape::XML::Node* write(Inkscape::XML::Document *xml_doc, Inkscape::XML::Node *repr, unsigned int flags) override;
 };
 
 #endif /* !SP_LINEAR_GRADIENT_H */
diff --git a/src/object/sp-radial-gradient.cpp b/src/object/sp-radial-gradient.cpp
index 271894ae2..79817143e 100644
--- a/src/object/sp-radial-gradient.cpp
+++ b/src/object/sp-radial-gradient.cpp
@@ -12,6 +12,7 @@
 #include "sp-radial-gradient.h"
 
 #include "attributes.h"
+#include "style.h"
 #include "xml/repr.h"
 
 #include <2geom/transforms.h>
@@ -48,6 +49,7 @@ void SPRadialGradient::build(SPDocument *document, Inkscape::XML::Node *repr) {
  * Set radial gradient attribute.
  */
 void SPRadialGradient::set(SPAttributeEnum key, gchar const *value) {
+
     switch (key) {
         case SP_ATTR_CX:
             if (!this->cx.read(value)) {
@@ -112,6 +114,31 @@ void SPRadialGradient::set(SPAttributeEnum key, gchar const *value) {
     }
 }
 
+void
+SPRadialGradient::update(SPCtx *ctx, guint flags)
+{
+    // To do: Verify flags.
+    if (flags & (SP_OBJECT_MODIFIED_FLAG | SP_OBJECT_STYLE_MODIFIED_FLAG | SP_OBJECT_VIEWPORT_MODIFIED_FLAG)) {
+
+        SPItemCtx const *ictx = reinterpret_cast<SPItemCtx const *>(ctx);
+
+        if (getUnits() == SP_GRADIENT_UNITS_USERSPACEONUSE) {
+            double w = ictx->viewport.width();
+            double h = ictx->viewport.height();
+            double d = sqrt ((w*w + h*h)/2.0);
+            double const em = style->font_size.computed;
+            double const ex = 0.5 * em;  // fixme: get x height from pango or libnrtype.
+
+            this->cx.update(em, ex, w);
+            this->cy.update(em, ex, h);
+            this->r.update(em, ex, d);
+            this->fx.update(em, ex, w);
+            this->fy.update(em, ex, h);
+            this->fr.update(em, ex, d);
+        }
+    }
+}
+
 /**
  * Write radial gradient attributes to associated repr.
  */
@@ -212,3 +239,14 @@ cairo_pattern_t* SPRadialGradient::pattern_new(cairo_t *ct, Geom::OptRect const
 
     return cp;
 }
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/object/sp-radial-gradient.h b/src/object/sp-radial-gradient.h
index b88ac7e2f..72c4dec55 100644
--- a/src/object/sp-radial-gradient.h
+++ b/src/object/sp-radial-gradient.h
@@ -26,8 +26,8 @@ typedef struct _cairo_pattern cairo_pattern_t;
 /** Radial gradient. */
 class SPRadialGradient : public SPGradient {
 public:
-	SPRadialGradient();
-	~SPRadialGradient() override;
+    SPRadialGradient();
+    ~SPRadialGradient() override;
 
     SVGLength cx;
     SVGLength cy;
@@ -39,9 +39,10 @@ public:
     cairo_pattern_t* pattern_new(cairo_t *ct, Geom::OptRect const &bbox, double opacity) override;
 
 protected:
-	void build(SPDocument *document, Inkscape::XML::Node *repr) override;
-	void set(SPAttributeEnum key, char const *value) override;
-	Inkscape::XML::Node* write(Inkscape::XML::Document *xml_doc, Inkscape::XML::Node *repr, unsigned int flags) override;
+    void build(SPDocument *document, Inkscape::XML::Node *repr) override;
+    void set(SPAttributeEnum key, char const *value) override;
+    void update(SPCtx *ctx, unsigned int flags) override;
+    Inkscape::XML::Node* write(Inkscape::XML::Document *xml_doc, Inkscape::XML::Node *repr, unsigned int flags) override;
 };
 
 #endif /* !SP_RADIAL_GRADIENT_H */