[PATCH 2/2] xwm: Scale icon if size is not the target size

[Scott Moreau]

This scales the icon cairo surface for the titlebar if it isn't the
right size.

shared/cairo-util: Add surface resizing function to be used for this
case and other potential cases.
---
 shared/cairo-util.c       | 61 +++++++++++++++++++++++++++++++++++++++++++++++
 shared/cairo-util.h       |  4 ++++
 xwayland/window-manager.c |  9 ++++++-
 3 files changed, 73 insertions(+), 1 deletion(-)

diff --git a/shared/cairo-util.c b/shared/cairo-util.c
index d71e0ed..b91b5bc 100644
--- a/shared/cairo-util.c
+++ b/shared/cairo-util.c
@@ -142,6 +142,67 @@ blur_surface(cairo_surface_t *surface, int margin)
 	return 0;
 }
 
+static cairo_surface_t *
+scale_surface(cairo_surface_t *source, cairo_filter_t filter,
+							double width, double height)
+{
+	cairo_surface_t *dest;
+	cairo_t *cr;
+	int old_width, old_height;
+
+	old_width = cairo_image_surface_get_width(source);
+	old_height = cairo_image_surface_get_height(source);
+
+	dest = cairo_surface_create_similar(source, CAIRO_CONTENT_COLOR_ALPHA,
+								width, height);
+	cr = cairo_create (dest);
+
+	cairo_scale (cr, width / old_width, height / old_height);
+	cairo_set_source_surface (cr, source, 0, 0);
+
+	cairo_pattern_set_extend (cairo_get_source(cr), CAIRO_EXTEND_REFLECT);
+
+	cairo_set_operator (cr, CAIRO_OPERATOR_SOURCE);
+
+	cairo_paint (cr);
+
+	cairo_destroy (cr);
+
+	cairo_surface_destroy(source);
+
+	return dest;
+}
+
+cairo_surface_t *
+cairo_resize_surface(cairo_surface_t *source, cairo_filter_t filter,
+							int width, int height)
+{
+	if (!filter)
+		filter = CAIRO_FILTER_BEST;
+
+	while((cairo_image_surface_get_width(source) / 2.0f) > width)
+		source = scale_surface(source, filter,
+				cairo_image_surface_get_width(source) / 2.0f,
+				cairo_image_surface_get_height(source));
+
+	while((cairo_image_surface_get_height(source) / 2.0f) > height)
+		source = scale_surface(source, filter,
+				cairo_image_surface_get_width(source),
+				cairo_image_surface_get_height(source) / 2.0f);
+
+	while((cairo_image_surface_get_width(source) * 2.0f) < width)
+		source = scale_surface(source, filter,
+				cairo_image_surface_get_width(source) * 2.0f,
+				cairo_image_surface_get_height(source));
+
+	while((cairo_image_surface_get_height(source) * 2.0f) < height)
+		source = scale_surface(source, filter,
+				cairo_image_surface_get_width(source),
+				cairo_image_surface_get_height(source) * 2.0f);
+
+	return scale_surface(source, filter, width, height);
+}
+
 void
 render_shadow(cairo_t *cr, cairo_surface_t *surface,
 	      int x, int y, int width, int height, int margin, int top_margin)
diff --git a/shared/cairo-util.h b/shared/cairo-util.h
index 6fd11f6..3bd2b0c 100644
--- a/shared/cairo-util.h
+++ b/shared/cairo-util.h
@@ -49,6 +49,10 @@ rounded_rect(cairo_t *cr, int x0, int y0, int x1, int y1, int radius);
 cairo_surface_t *
 load_cairo_surface(const char *filename);
 
+cairo_surface_t *
+cairo_resize_surface(cairo_surface_t *source, cairo_filter_t filter,
+							int width, int height);
+
 struct theme {
 	cairo_surface_t *active_frame;
 	cairo_surface_t *inactive_frame;
diff --git a/xwayland/window-manager.c b/xwayland/window-manager.c
index 8b7d2f6..741fa1e 100644
--- a/xwayland/window-manager.c
+++ b/xwayland/window-manager.c
@@ -1409,6 +1409,7 @@ get_icon_size_from_data(int target_width, int target_height,
 	return ret;
 }
 
+#define ICON_SIZE 16
 static void
 weston_wm_handle_icon(struct weston_wm *wm, struct weston_wm_window *window)
 {
@@ -1430,7 +1431,8 @@ weston_wm_handle_icon(struct weston_wm *wm, struct weston_wm_window *window)
 
 	data = xcb_get_property_value(reply);
 
-	data = get_icon_size_from_data(16, 16, &width, &height, length, data);
+	data = get_icon_size_from_data(ICON_SIZE, ICON_SIZE,
+									&width, &height, length, data);
 
 	/* Some checks against malformed input. */
 	if (!data || width == 0 || height == 0 || length < 2 + width * height)
@@ -1447,11 +1449,16 @@ weston_wm_handle_icon(struct weston_wm *wm, struct weston_wm_window *window)
 		return;
 	}
 
+	if (width != ICON_SIZE || height != ICON_SIZE)
+		new_surface =
+			cairo_resize_surface(new_surface, 0, ICON_SIZE, ICON_SIZE);
+
 	if (window->frame)
 		frame_set_icon(window->frame, new_surface);
 	else /* We don’t have a frame yet */
 		window->icon_surface = new_surface;
 }
+#undef ICON_SIZE
 
 static void
 weston_wm_handle_property_notify(struct weston_wm *wm, xcb_generic_event_t *event)
-- 
2.7.4