[gtk+/picture: 16/22] testpicture: Add scribble area
- From: Benjamin Otte <otte src gnome org>
- To: commits-list gnome org
- Cc:
- Subject: [gtk+/picture: 16/22] testpicture: Add scribble area
- Date: Mon, 14 Feb 2011 18:35:11 +0000 (UTC)
commit 4c7c292a048388d60020a770551d2a37b001016e
Author: Benjamin Otte <otte redhat com>
Date: Wed Feb 9 23:39:13 2011 +0100
testpicture: Add scribble area
Requires a custom picture subclass. And all the code in 180 lines,
woohoo!
tests/testpicture.c | 179 ++++++++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 177 insertions(+), 2 deletions(-)
---
diff --git a/tests/testpicture.c b/tests/testpicture.c
index 26b6a9d..49937ef 100644
--- a/tests/testpicture.c
+++ b/tests/testpicture.c
@@ -2,6 +2,64 @@
#include <math.h>
+
+
+#define IMAGE_TYPE_PICTURE (image_picture_get_type ())
+#define IMAGE_PICTURE(o) (G_TYPE_CHECK_INSTANCE_CAST ((o), IMAGE_TYPE_PICTURE, ImagePicture))
+#define IMAGE_PICTURE_CLASS(k) (G_TYPE_CHECK_CLASS_CAST((k), IMAGE_TYPE_PICTURE, ImagePictureClass))
+#define IMAGE_IS_PICTURE(o) (G_TYPE_CHECK_INSTANCE_TYPE ((o), IMAGE_TYPE_PICTURE))
+#define IMAGE_IS_PICTURE_CLASS(k) (G_TYPE_CHECK_CLASS_TYPE ((k), IMAGE_TYPE_PICTURE))
+#define IMAGE_PICTURE_GET_CLASS(o) (G_TYPE_INSTANCE_GET_CLASS ((o), IMAGE_TYPE_PICTURE, ImagePictureClass))
+
+typedef struct _ImagePicture ImagePicture;
+typedef GdkPictureClass ImagePictureClass;
+struct _ImagePicture {
+ GdkPicture picture;
+ cairo_surface_t *surface;
+};
+
+G_DEFINE_TYPE (ImagePicture, image_picture, GDK_TYPE_PICTURE)
+
+static void
+image_picture_finalize (GObject *object)
+{
+ cairo_surface_destroy (IMAGE_PICTURE (object)->surface);
+
+ G_OBJECT_CLASS (image_picture_parent_class)->finalize (object);
+}
+
+static cairo_surface_t *
+image_picture_ref_surface (GdkPicture *picture)
+{
+ return cairo_surface_reference (IMAGE_PICTURE (picture)->surface);
+}
+
+static void
+image_picture_class_init (ImagePictureClass *klass)
+{
+ GObjectClass *object_class = G_OBJECT_CLASS (klass);
+ GdkPictureClass *picture_class = GDK_PICTURE_CLASS (klass);
+
+ object_class->finalize = image_picture_finalize;
+
+ picture_class->ref_surface = image_picture_ref_surface;
+}
+
+static void
+image_picture_init (ImagePicture *picture)
+{
+ picture->surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32, 100, 100);
+ gdk_picture_resized (GDK_PICTURE (picture), 100, 100);
+}
+
+static GdkPicture *
+image_picture_new (void)
+{
+ return g_object_new (IMAGE_TYPE_PICTURE, NULL);
+}
+
+
+
#define SLOW_TYPE_INPUT_STREAM (slow_input_stream_get_type ())
#define SLOW_INPUT_STREAM(o) (G_TYPE_CHECK_INSTANCE_CAST ((o), SLOW_TYPE_INPUT_STREAM, SlowInputStream))
#define SLOW_INPUT_STREAM_CLASS(k) (G_TYPE_CHECK_CLASS_CAST((k), SLOW_TYPE_INPUT_STREAM, SlowInputStreamClass))
@@ -69,6 +127,8 @@ slow_input_stream_new (GInputStream *base_stream)
return g_object_new (slow_input_stream_get_type (), "base-stream", base_stream, NULL);
}
+
+
typedef struct _Demo Demo;
struct _Demo
{
@@ -194,11 +254,126 @@ create_icon_set_picture (Demo *demo)
gtk_icon_set_unref (set);
}
+static GdkRGBA scribble_colors[2] =
+{
+ { 0.0, 0.0, 0.0, 1.0 },
+ { 0.0, 0.0, 0.0, 0.0 }
+};
+
+/* Draw a rectangle onto the picture */
+static void
+scribble (ImagePicture * picture,
+ gdouble x,
+ gdouble y,
+ const GdkRGBA *color)
+{
+ GdkRectangle update_rect;
+ cairo_t *cr;
+
+ update_rect.x = x - 3;
+ update_rect.y = y - 3;
+ update_rect.width = 6;
+ update_rect.height = 6;
+
+ /* Paint to the surface, where we store our state */
+ cr = cairo_create (picture->surface);
+
+ cairo_set_operator (cr, CAIRO_OPERATOR_SOURCE);
+ gdk_cairo_set_source_rgba (cr, color);
+ gdk_cairo_rectangle (cr, &update_rect);
+ cairo_fill (cr);
+
+ cairo_destroy (cr);
+
+ /* Now invalidate the affected region of the drawing area. */
+ gdk_picture_changed_rect (GDK_PICTURE (picture), &update_rect);
+}
+
+static gboolean
+scribble_button_press_event (GtkWidget *widget,
+ GdkEventButton *event,
+ ImagePicture *picture)
+{
+ if (event->button == 1)
+ scribble (picture, event->x, event->y, &scribble_colors[0]);
+ else if (event->button == 3)
+ scribble (picture, event->x, event->y, &scribble_colors[1]);
+
+ /* We've handled the event, stop processing */
+ return TRUE;
+}
+
+static gboolean
+scribble_motion_notify_event (GtkWidget *widget,
+ GdkEventMotion *event,
+ ImagePicture *picture)
+{
+ int x, y;
+ GdkModifierType state;
+
+ /* This call is very important; it requests the next motion event.
+ * If you don't call gdk_window_get_pointer() you'll only get
+ * a single motion event. The reason is that we specified
+ * GDK_POINTER_MOTION_HINT_MASK to gtk_widget_set_events().
+ * If we hadn't specified that, we could just use event->x, event->y
+ * as the pointer location. But we'd also get deluged in events.
+ * By requesting the next event as we handle the current one,
+ * we avoid getting a huge number of events faster than we
+ * can cope.
+ */
+
+ gdk_window_get_pointer (event->window, &x, &y, &state);
+
+ if (state & GDK_BUTTON1_MASK)
+ scribble (picture, x, y, &scribble_colors[0]);
+ if (state & GDK_BUTTON3_MASK)
+ scribble (picture, x, y, &scribble_colors[1]);
+
+ /* We've handled it, stop processing */
+ return TRUE;
+}
+
+static void
+create_scribble_area (Demo *demo)
+{
+ GtkWidget *frame, *image, *eventbox;
+
+ demo->picture = image_picture_new ();
+
+ demo->widget = gtk_alignment_new (0.5, 0.5, 0, 0);
+
+ frame = gtk_frame_new (NULL);
+ gtk_frame_set_shadow_type (GTK_FRAME (frame), GTK_SHADOW_IN);
+ gtk_container_add (GTK_CONTAINER (demo->widget), frame);
+
+ eventbox = gtk_event_box_new ();
+ gtk_container_add (GTK_CONTAINER (frame), eventbox);
+
+ /* Event signals */
+
+ g_signal_connect (eventbox, "motion-notify-event",
+ G_CALLBACK (scribble_motion_notify_event), demo->picture);
+ g_signal_connect (eventbox, "button-press-event",
+ G_CALLBACK (scribble_button_press_event), demo->picture);
+
+ /* Ask to receive events the drawing area doesn't normally
+ * subscribe to
+ */
+ gtk_widget_add_events (eventbox,
+ GDK_BUTTON_PRESS_MASK
+ | GDK_POINTER_MOTION_MASK
+ | GDK_POINTER_MOTION_HINT_MASK);
+
+ image = gtk_image_new_from_picture (demo->picture);
+ gtk_container_add (GTK_CONTAINER (eventbox), image);
+}
+
Demo demos[] = {
{ "Slowly loading image", create_slowly_loading_image, NULL, NULL },
{ "Another slowly loading image", create_slowly_loading_image, NULL, NULL },
{ "Named theme icons", create_stock_picture, NULL, NULL },
- { "Icon Set", create_icon_set_picture, NULL, NULL }
+ { "Icon Set", create_icon_set_picture, NULL, NULL },
+ { "Scribble Area", create_scribble_area, NULL, NULL }
};
static guint rotation = 0;
@@ -389,7 +564,7 @@ main (int argc, char **argv)
gtk_init (&argc, &argv);
- //gdk_window_set_debug_updates (TRUE);
+ gdk_window_set_debug_updates (TRUE);
window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
gtk_window_set_title (GTK_WINDOW (window), "Pictures");
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