CanvasGL: support drag and zoom gestures

horizon-eda · Feb 23, 2020 · 38ff613 · 38ff613
1 parent c91949a
commit 38ff613
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Showing 3 changed files with 79 additions and 0 deletions.
diff --git a/src/canvas/canvas_gl.cpp b/src/canvas/canvas_gl.cpp
@@ -48,6 +48,63 @@ CanvasGL::CanvasGL()
 
     update_palette_colors();
     layer_colors = appearance.layer_colors;
+
+    gesture_zoom = Gtk::GestureZoom::create(*this);
+    gesture_zoom->signal_begin().connect(sigc::mem_fun(*this, &CanvasGL::zoom_gesture_begin_cb));
+    gesture_zoom->signal_update().connect(sigc::mem_fun(*this, &CanvasGL::zoom_gesture_update_cb));
+    gesture_zoom->set_propagation_phase(Gtk::PHASE_BUBBLE);
+
+    gesture_drag = Gtk::GestureDrag::create(*this);
+    gesture_drag->signal_begin().connect(sigc::mem_fun(*this, &CanvasGL::drag_gesture_begin_cb));
+    gesture_drag->signal_update().connect(sigc::mem_fun(*this, &CanvasGL::drag_gesture_update_cb));
+    gesture_drag->set_propagation_phase(Gtk::PHASE_BUBBLE);
+    gesture_drag->set_touch_only(true);
+}
+
+void CanvasGL::zoom_gesture_begin_cb(GdkEventSequence *seq)
+{
+    if (pan_dragging) {
+        gesture_zoom->set_state(Gtk::EVENT_SEQUENCE_DENIED);
+        return;
+    }
+    gesture_zoom_scale_orig = scale;
+    gesture_zoom_offset_orig = offset;
+    double cx, cy;
+    gesture_zoom->get_bounding_box_center(cx, cy);
+    gesture_zoom_pos_orig = Coordf(cx, cy);
+    gesture_zoom->set_state(Gtk::EVENT_SEQUENCE_CLAIMED);
+}
+
+void CanvasGL::zoom_gesture_update_cb(GdkEventSequence *seq)
+{
+    auto delta = gesture_zoom->get_scale_delta();
+    double cx, cy;
+    gesture_zoom->get_bounding_box_center(cx, cy);
+    set_scale(cx, cy, gesture_zoom_scale_orig * delta);
+    offset = gesture_zoom_offset_orig + Coordf(cx, cy) - gesture_zoom_pos_orig;
+    update_viewmat();
+    queue_draw();
+}
+
+void CanvasGL::drag_gesture_begin_cb(GdkEventSequence *seq)
+{
+    inhibit_drag_selection();
+    if (pan_dragging) {
+        gesture_drag->set_state(Gtk::EVENT_SEQUENCE_DENIED);
+    }
+    else {
+        gesture_drag_offset_orig = offset;
+        gesture_drag->set_state(Gtk::EVENT_SEQUENCE_CLAIMED);
+    }
+}
+void CanvasGL::drag_gesture_update_cb(GdkEventSequence *seq)
+{
+    double x, y;
+    if (gesture_drag->get_offset(x, y)) {
+        offset = gesture_drag_offset_orig + Coordf(x, y);
+        update_viewmat();
+        queue_draw();
+    }
 }
 
 void CanvasGL::on_size_allocate(Gtk::Allocation &alloc)

diff --git a/src/canvas/canvas_gl.hpp b/src/canvas/canvas_gl.hpp
@@ -247,6 +247,19 @@ class CanvasGL : public Canvas, public Gtk::GLArea {
 
     SelectionMode selection_mode = SelectionMode::HOVER;
 
+    Glib::RefPtr<Gtk::GestureZoom> gesture_zoom;
+    void zoom_gesture_begin_cb(GdkEventSequence *seq);
+    void zoom_gesture_update_cb(GdkEventSequence *seq);
+    Coord<float> gesture_zoom_pos_orig;
+    Coord<float> gesture_zoom_offset_orig;
+    float gesture_zoom_scale_orig = 1;
+
+    Glib::RefPtr<Gtk::GestureDrag> gesture_drag;
+    Coord<float> gesture_drag_offset_orig;
+
+    void drag_gesture_begin_cb(GdkEventSequence *seq);
+    void drag_gesture_update_cb(GdkEventSequence *seq);
+
 protected:
     void on_size_allocate(Gtk::Allocation &alloc) override;
     void on_realize() override;

diff --git a/src/canvas/pan.cpp b/src/canvas/pan.cpp
@@ -6,6 +6,9 @@
 namespace horizon {
 void CanvasGL::pan_drag_begin(GdkEventButton *button_event)
 {
+    if (gesture_zoom->is_recognized() || gesture_drag->is_recognized())
+        return;
+
     gdouble x, y;
     gdk_event_get_coords((GdkEvent *)button_event, &x, &y);
     if (button_event->button == 2 || (button_event->button == 1 && (button_event->state & Gdk::SHIFT_MASK))) {
@@ -84,6 +87,10 @@ void CanvasGL::set_scale(float x, float y, float scale_new)
         pan_offset_orig.x += xi;
         pan_offset_orig.y += yi;
     }
+    if (gesture_zoom->is_recognized()) {
+        gesture_zoom_offset_orig.x += xi;
+        gesture_zoom_offset_orig.y += yi;
+    }
     update_viewmat();
     queue_draw();
 }
@@ -118,6 +125,8 @@ static int tick_cb(GtkWidget *cwidget, GdkFrameClock *frame_clock, gpointer user
 
 void CanvasGL::pan_zoom(GdkEventScroll *scroll_event, bool to_cursor)
 {
+    if (gesture_zoom->is_recognized() || gesture_drag->is_recognized())
+        return;
     gdouble x, y;
     if (to_cursor) {
         gdk_event_get_coords((GdkEvent *)scroll_event, &x, &y);