After snapping, show a tooltip together with the snap indicator

(bzr r7296)

3 files changed, 156 insertions, 48 deletions

diff --git a/src/display/snap-indicator.cpp b/src/display/snap-indicator.cpp
index 98358dbab..1785da7b9 100644
--- a/src/display/snap-indicator.cpp
+++ b/src/display/snap-indicator.cpp
@@ -5,8 +5,8 @@
  *   Johan Engelen
  *   Diederik van Lierop
  *
- * Copyright (C) Johan Engelen 2008 <j.b.c.engelen@utwente.nl>
- * Copyright (C) Diederik van Lierop 2008 <mail@diedenrezi.nl>
+ * Copyright (C) Johan Engelen 2009 <j.b.c.engelen@utwente.nl>
+ * Copyright (C) Diederik van Lierop 2009 <mail@diedenrezi.nl>
  *
  * Released under GNU GPL, read the file 'COPYING' for more information
  */
@@ -18,6 +18,8 @@
 #include "display/sodipodi-ctrl.h"
 #include "knot.h"
 #include "preferences.h"
+#include <glibmm/i18n.h>
+#include <gtk/gtk.h>
 
 namespace Inkscape {
 namespace Display {
@@ -53,48 +55,94 @@ SnapIndicator::set_new_snaptarget(Inkscape::SnappedPoint const p)
     bool value = prefs->getBool("/options/snapindicator/value", true);
 
     if (value) {
-        SPCanvasItem * canvasitem = NULL;
+        gchar *target_name = _("UNDEFINED");
         switch (p.getTarget()) {
-            /// @todo  add the different kinds of snapindicator visuals
-            case SNAPTARGET_NODE:
-                canvasitem = sp_canvas_item_new(sp_desktop_tempgroup (_desktop),
-                                                SP_TYPE_CTRL,
-                                                "anchor", GTK_ANCHOR_CENTER,
-                                                "size", 10.0,
-                                                "stroked", TRUE,
-                                                "stroke_color", 0xf000f0ff,
-                                                "mode", SP_KNOT_MODE_XOR,
-                                                "shape", SP_KNOT_SHAPE_DIAMOND,
-                                                NULL );
-                break;
-            case SNAPTARGET_GRID:
+			case SNAPTARGET_UNDEFINED:
+				target_name = _("UNDEFINED");
+				break;
+			case SNAPTARGET_GRID:
+            	target_name = _("grid line");
+            	break;
             case SNAPTARGET_GRID_INTERSECTION:
+            	target_name = _("grid intersection");
+            	break;
             case SNAPTARGET_GUIDE:
+            	target_name = _("guide");
+            	break;
             case SNAPTARGET_GUIDE_INTERSECTION:
+            	target_name = _("guide intersection");
+            	break;
             case SNAPTARGET_GRID_GUIDE_INTERSECTION:
-            case SNAPTARGET_PATH:
+            	target_name = _("grid-guide intersection");
+            	break;
+            case SNAPTARGET_NODE:
+				target_name = _("node");
+				break;
+			case SNAPTARGET_PATH:
+            	target_name = _("path");
+            	break;
             case SNAPTARGET_PATH_INTERSECTION:
+            	target_name = _("path intersection");
+            	break;
             case SNAPTARGET_BBOX_CORNER:
+            	target_name = _("bounding box corner");
+            	break;
             case SNAPTARGET_BBOX_EDGE:
+            	target_name = _("bounding box side");
+            	break;
             case SNAPTARGET_GRADIENT:
-            case SNAPTARGET_UNDEFINED:
+            	target_name = _("gradient");
+            	break;
+            case SNAPTARGET_PAGE_BORDER:
+            	target_name = _("page border");
+				break;
             default:
-                canvasitem = sp_canvas_item_new(sp_desktop_tempgroup (_desktop),
-                                                SP_TYPE_CTRL,
-                                                "anchor", GTK_ANCHOR_CENTER,
-                                                "size", 10.0,
-                                                "stroked", TRUE,
-                                                "stroke_color", 0xf000f0ff,
-                                                "mode", SP_KNOT_MODE_XOR,
-                                                "shape", SP_KNOT_SHAPE_CROSS,
-                                                NULL );
+            	g_warning("Snap target has not yet been defined!");
                 break;
         }
+        // std::cout << "Snapped to: " << target_name << std::endl;
 
-        SP_CTRL(canvasitem)->moveto(p.getPoint());
-        remove_snapsource(); // Don't set both the source and target indicators, as these will overlap
-        _snaptarget = _desktop->add_temporary_canvasitem(canvasitem, 1000); // TODO add preference for snap indicator timeout
-    }
+        // Display the snap indicator (i.e. the cross)
+        SPCanvasItem * canvasitem = NULL;
+		if (p.getTarget() == SNAPTARGET_NODE) {
+			canvasitem = sp_canvas_item_new(sp_desktop_tempgroup (_desktop),
+											SP_TYPE_CTRL,
+											"anchor", GTK_ANCHOR_CENTER,
+											"size", 10.0,
+											"stroked", TRUE,
+											"stroke_color", 0xf000f0ff,
+											"mode", SP_KNOT_MODE_XOR,
+											"shape", SP_KNOT_SHAPE_DIAMOND,
+											NULL );
+		} else {
+			canvasitem = sp_canvas_item_new(sp_desktop_tempgroup (_desktop),
+											SP_TYPE_CTRL,
+											"anchor", GTK_ANCHOR_CENTER,
+											"size", 10.0,
+											"stroked", TRUE,
+											"stroke_color", 0xf000f0ff,
+											"mode", SP_KNOT_MODE_XOR,
+											"shape", SP_KNOT_SHAPE_CROSS,
+											NULL );
+		}
+
+		const int timeout_val = 1000; // TODO add preference for snap indicator timeout?
+
+		SP_CTRL(canvasitem)->moveto(p.getPoint());
+		remove_snapsource(); // Don't set both the source and target indicators, as these will overlap
+		_snaptarget = _desktop->add_temporary_canvasitem(canvasitem, timeout_val);
+
+        // Display the tooltip
+		GtkSettings *settings = gtk_widget_get_settings (&(_desktop->canvas->widget));
+		// If we set the timeout too short, then the tooltip might not show at all (most noticeable when a long snap delay is active)
+		g_object_set(settings, "gtk-tooltip-timeout", 200, NULL); // tooltip will be shown after x msec.
+        gtk_widget_set_tooltip_text(&(_desktop->canvas->widget), target_name);
+        // has_tooltip will be true by now because gtk_widget_set_has_tooltip() has been called implicitly
+        update_tooltip();
+        // The snap indicator will be removed automatically because it's a temporary canvas item; the tooltip
+        // however must be removed manually, so we'll create a timer to that end
+        Glib::signal_timeout().connect(sigc::mem_fun(*this, &SnapIndicator::remove_tooltip), timeout_val);
+	}
 }
 
 void
@@ -104,6 +152,8 @@ SnapIndicator::remove_snaptarget()
         _desktop->remove_temporary_canvasitem(_snaptarget);
         _snaptarget = NULL;
     }
+
+    remove_tooltip();
 }
 
 void
@@ -141,11 +191,46 @@ SnapIndicator::remove_snapsource()
     }
 }
 
+// Shows or hides the tooltip
+void SnapIndicator::update_tooltip() const
+{
+	// When using gtk_widget_trigger_tooltip_query, the tooltip will for some reason always popup
+	// in the upper-left corner of the screen (probably at (0,0)). As a workaround we'll create
+	// a motion event instead, which will also trigger the tooltip
+	gint x, y;
+	GdkWindow *window;
+
+	GdkDisplay *display = gdk_display_get_default();
+	window = gdk_display_get_window_at_pointer(display, &x, &y);
+	if (window) {
+		GdkEvent *event = gdk_event_new(GDK_MOTION_NOTIFY);
+		event->motion.window = window;
+		event->motion.x = x;
+		event->motion.y = y;
+		event->motion.is_hint = FALSE;
+
+		gdk_window_get_origin(window, &x, &y);
+		event->motion.x_root = event->motion.x + x;
+		event->motion.y_root = event->motion.y + y;
+
+		gtk_main_do_event(event);
+	}
+}
+
+// Can be called either directly or through a timer
+bool
+SnapIndicator::remove_tooltip() const
+{
+    gtk_widget_set_has_tooltip (&(_desktop->canvas->widget), false);
+    gtk_widget_trigger_tooltip_query(&(_desktop->canvas->widget));
+    return false;
+}
 
 
 } //namespace Display
 } /* namespace Inkscape */
 
+
 /*
   Local Variables:
   mode:c++
diff --git a/src/display/snap-indicator.h b/src/display/snap-indicator.h
index d2c6dba8e..672d2e78c 100644
--- a/src/display/snap-indicator.h
+++ b/src/display/snap-indicator.h
@@ -28,10 +28,10 @@ public:
 
     void set_new_snaptarget(Inkscape::SnappedPoint const p);
     void remove_snaptarget();
-    
+
     void set_new_snapsource(Geom::Point const p);
     void remove_snapsource();
-    
+
 protected:
     TemporaryItem *_snaptarget;
     TemporaryItem *_snapsource;
@@ -40,6 +40,8 @@ protected:
 private:
     SnapIndicator(const SnapIndicator&);
     SnapIndicator& operator=(const SnapIndicator&);
+    void update_tooltip() const;
+    bool remove_tooltip() const;
 };
 
 } //namespace Display
diff --git a/src/display/sp-canvas.cpp b/src/display/sp-canvas.cpp
index edd64f021..141e10611 100644
--- a/src/display/sp-canvas.cpp
+++ b/src/display/sp-canvas.cpp
@@ -938,6 +938,7 @@ static gint sp_canvas_key (GtkWidget *widget, GdkEventKey *event);
 static gint sp_canvas_crossing (GtkWidget *widget, GdkEventCrossing *event);
 static gint sp_canvas_focus_in (GtkWidget *widget, GdkEventFocus *event);
 static gint sp_canvas_focus_out (GtkWidget *widget, GdkEventFocus *event);
+static gboolean sp_canvas_query_tooltip (GtkWidget *widget, gint x, gint y, gboolean keyboard_mode, GtkTooltip *tooltip);
 
 static GtkWidgetClass *canvas_parent_class;
 
@@ -1050,6 +1051,8 @@ sp_canvas_init (SPCanvas *canvas)
     canvas->watchdog_id = 0;
     canvas->watchdog_event = NULL;
     canvas->context_snap_delay_active = false;
+
+    g_signal_connect(&(canvas->widget), "query-tooltip", G_CALLBACK (sp_canvas_query_tooltip), NULL);
 }
 
 /**
@@ -1609,20 +1612,19 @@ sp_canvas_motion (GtkWidget *widget, GdkEventMotion *event)
 
     SPDesktop *dt = SP_ACTIVE_DESKTOP;
 
-    // Snap when speed drops below e.g. 0.02 px/msec, or when no motion events have occured for some period.
-	// i.e. snap when we're at stand still. A speed threshold enforces snapping for tablets, which might never
-	// be fully at stand still and might keep spitting out motion events.
-	if (canvas->context_snap_delay_active && dt && dt->namedview->snap_manager.snapprefs.getSnapEnabledGlobally()) {
-		Geom::Point event_pos(event->x, event->y);
-		guint32 event_t = gdk_event_get_time ( (GdkEvent *) event );
-
+    if (canvas->context_snap_delay_active && dt && dt->namedview->snap_manager.snapprefs.getSnapEnabledGlobally()) {
+    	// Snap when speed drops below e.g. 0.02 px/msec, or when no motion events have occurred for some period.
+		// i.e. snap when we're at stand still. A speed threshold enforces snapping for tablets, which might never
+		// be fully at stand still and might keep spitting out motion events.
 		dt->namedview->snap_manager.snapprefs.setSnapPostponedGlobally(true); // put snapping on hold
 
+    	Geom::Point event_pos(event->x, event->y);
+		guint32 event_t = gdk_event_get_time ( (GdkEvent *) event );
+
 		if (prev_pos) {
 			Geom::Coord dist = Geom::L2(event_pos - *prev_pos);
 			guint32 delta_t = event_t - prev_time;
 			gdouble speed = delta_t > 0 ? dist/delta_t : 1000;
-			// std::cout << "speed = " << speed << " px/msec " << "| time passed = " << delta_t << " msec" << std::endl;
 			if (speed > 0.02) { // Jitter threshold, might be needed for tablets
 				// We're moving fast, so postpone any snapping until the next GDK_MOTION_NOTIFY event. We
 				// will keep on postponing the snapping as long as the speed is high.
@@ -1654,13 +1656,11 @@ sp_canvas_motion (GtkWidget *widget, GdkEventMotion *event)
 	}
 
     canvas->state = event->state;
-    pick_current_item (canvas, (GdkEvent *) event);
-
-    status = emit_event (canvas, (GdkEvent *) event);
-
-    if (event->is_hint) {
-        request_motions(widget->window, event);
-    }
+	pick_current_item (canvas, (GdkEvent *) event);
+	status = emit_event (canvas, (GdkEvent *) event);
+	if (event->is_hint) {
+		request_motions(widget->window, event);
+	}
 
     return status;
 }
@@ -1670,6 +1670,7 @@ gboolean sp_canvas_snap_watchdog_callback(gpointer data)
 	// Snap NOW! For this the "postponed" flag will be reset and an the last motion event will be repeated
 	SPCanvas *canvas = reinterpret_cast<SPCanvas *>(data);
 	if (!canvas->watchdog_event) {
+		// This might occur when this method is called directly, i.e. not through the timer
 		return FALSE;
 	}
 
@@ -2164,6 +2165,26 @@ sp_canvas_focus_out (GtkWidget *widget, GdkEventFocus *event)
         return FALSE;
 }
 
+
+static gboolean sp_canvas_query_tooltip (GtkWidget  *widget,
+		  gint        x,
+		  gint        y,
+		  gboolean	  keyboard_mode,
+		  GtkTooltip *tooltip)
+{
+	// We're not really doing anything special here, so we might just as well remove sp_canvas_query_tooltip
+	// all together (and stop listening to the query_tooltip signal. We might make a custom tooltip however
+	// someday, for example to display icons instead of just plain text. In that case we will need this call
+	// so that's why I'm leaving it here for the time being.
+
+	if (canvas_parent_class->query_tooltip) {
+		return canvas_parent_class->query_tooltip (widget, x, y, keyboard_mode, tooltip);
+	}
+
+	return false;
+}
+
+
 /**
  * Helper that repaints the areas in the canvas that need it.
  *