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gtk-demo: Port the drawingarea demo to a gesture

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Use a drag gesture here, just like in the drawing example.
This commit is contained in:
Matthias Clasen 2018-01-01 10:09:31 -05:00
parent c9267e70a9
commit 473bbeb475
1 changed files with 33 additions and 34 deletions
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67
demos/gtk-demo/drawingarea.c
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@ -89,42 +89,38 @@ draw_brush (GtkWidget *widget,
gtk_widget_queue_draw_area (widget, update_rect.x, update_rect.y, update_rect.width, update_rect.height);
}
static gboolean
scribble_button_press_event (GtkWidget *widget,
GdkEventButton *event,
gpointer data)
static double start_x;
static double start_y;
static void
drag_begin (GtkGestureDrag *gesture,
double x,
double y,
GtkWidget *area)
{
double x, y;
guint button;
start_x = x;
start_y = y;
gdk_event_get_button ((GdkEvent *)event, &button);
gdk_event_get_coords ((GdkEvent *)event, &x, &y);
if (button == GDK_BUTTON_PRIMARY)
draw_brush (widget, x, y);
/* We've handled the event, stop processing */
return TRUE;
draw_brush (area, x, y);
}
static gboolean
scribble_motion_notify_event (GtkWidget *widget,
GdkEventMotion *event,
gpointer data)
static void
drag_update (GtkGestureDrag *gesture,
double x,
double y,
GtkWidget *area)
{
double x, y;
GdkModifierType state;
gdk_event_get_state ((GdkEvent *)event, &state);
gdk_event_get_coords ((GdkEvent *)event, &x, &y);
if (state & GDK_BUTTON1_MASK)
draw_brush (widget, x, y);
/* We've handled it, stop processing */
return TRUE;
draw_brush (area, start_x + x, start_y + y);
}
static void
drag_end (GtkGestureDrag *gesture,
double x,
double y,
GtkWidget *area)
{
draw_brush (area, start_x + x, start_y + y);
}
static void
checkerboard_draw (GtkDrawingArea *da,
@ -189,6 +185,7 @@ do_drawingarea (GtkWidget *do_widget)
GtkWidget *vbox;
GtkWidget *da;
GtkWidget *label;
GtkGesture *drag;
if (!window)
{
@ -247,11 +244,13 @@ do_drawingarea (GtkWidget *do_widget)
g_signal_connect (da, "size-allocate",
G_CALLBACK (scribble_size_allocate), NULL);
/* Event signals */
g_signal_connect (da, "motion-notify-event",
G_CALLBACK (scribble_motion_notify_event), NULL);
g_signal_connect (da, "button-press-event",
G_CALLBACK (scribble_button_press_event), NULL);
drag = gtk_gesture_drag_new (da);
gtk_gesture_single_set_button (GTK_GESTURE_SINGLE (drag), GDK_BUTTON_PRIMARY);
g_object_set_data_full (G_OBJECT (da), "drag", drag, g_object_unref);
g_signal_connect (drag, "drag-begin", G_CALLBACK (drag_begin), da);
g_signal_connect (drag, "drag-update", G_CALLBACK (drag_update), da);
g_signal_connect (drag, "drag-begin", G_CALLBACK (drag_end), da);
}
if (!gtk_widget_get_visible (window))