[PATCH 5/5] desktop shell: resize background and panel when an output switches mode

[David Fort]

When an output permanently switches mode, the desktop shell must be notified so
that the misc components can resize to the new size of the output. This patch also
fixes the coodinates of "other" outputs when the resize occurs.

Signed-off-by: David Fort <contact at hardening-consulting.com>
---
 desktop-shell/shell.c | 34 ++++++++++++++++++++++++++++++++++
 desktop-shell/shell.h |  1 +
 src/compositor.c      | 33 ++++++++++++++++++++++-----------
 src/compositor.h      |  1 +
 4 files changed, 58 insertions(+), 11 deletions(-)

diff --git a/desktop-shell/shell.c b/desktop-shell/shell.c
index cd269a8..1c1c993 100644
--- a/desktop-shell/shell.c
+++ b/desktop-shell/shell.c
@@ -6368,11 +6368,43 @@ handle_output_destroy(struct wl_listener *listener, void *data)
 	shell_for_each_layer(shell, shell_output_destroy_move_layer, output);
 
 	wl_list_remove(&output_listener->destroy_listener.link);
+	wl_list_remove(&output_listener->resized_listener.link);
 	wl_list_remove(&output_listener->link);
 	free(output_listener);
 }
 
 static void
+shell_output_resize_layer(struct desktop_shell *shell,
+				struct weston_layer *layer,
+				void *data)
+{
+	struct weston_output *output = data;
+	struct weston_view *view;
+
+	wl_list_for_each(view, &layer->view_list.link, layer_link.link) {
+		if (view->output != output)
+			continue;
+
+		weston_desktop_shell_send_configure(shell->child.desktop_shell, 0,
+				view->surface->resource,
+				output->width,
+				output->height);
+	}
+}
+
+
+static void
+handle_output_resized(struct wl_listener *listener, void *data)
+{
+	struct shell_output *output_listener =
+		container_of(listener, struct shell_output, resized_listener);
+	struct weston_output *output = output_listener->output;
+	struct desktop_shell *shell = output_listener->shell;
+
+	shell_for_each_layer(shell, shell_output_resize_layer, output);
+}
+
+static void
 create_shell_output(struct desktop_shell *shell,
 					struct weston_output *output)
 {
@@ -6387,6 +6419,8 @@ create_shell_output(struct desktop_shell *shell,
 	shell_output->destroy_listener.notify = handle_output_destroy;
 	wl_signal_add(&output->destroy_signal,
 		      &shell_output->destroy_listener);
+	shell_output->resized_listener.notify = handle_output_resized;
+	wl_signal_add(&output->compositor->output_resized_signal, &shell_output->resized_listener);
 	wl_list_insert(shell->output_list.prev, &shell_output->link);
 }
 
diff --git a/desktop-shell/shell.h b/desktop-shell/shell.h
index b430fa2..5457923 100644
--- a/desktop-shell/shell.h
+++ b/desktop-shell/shell.h
@@ -112,6 +112,7 @@ struct shell_output {
 	struct desktop_shell  *shell;
 	struct weston_output  *output;
 	struct exposay_output eoutput;
+	struct wl_listener    resized_listener;
 	struct wl_listener    destroy_listener;
 	struct wl_list        link;
 };
diff --git a/src/compositor.c b/src/compositor.c
index 5500197..a747945 100644
--- a/src/compositor.c
+++ b/src/compositor.c
@@ -143,6 +143,11 @@ static void weston_mode_switch_finish(struct weston_output *output,
 	}
 }
 
+
+static void
+weston_compositor_resize_output(struct weston_compositor *compositor,
+				struct weston_output *resized_output, int delta_width);
+
 WL_EXPORT int
 weston_output_mode_set_native(struct weston_output *output,
 			      struct weston_mode *mode,
@@ -150,6 +155,7 @@ weston_output_mode_set_native(struct weston_output *output,
 {
 	int ret;
 	int mode_changed = 0, scale_changed = 0;
+	struct weston_mode *old_mode;
 
 	if (!output->switch_mode)
 		return -1;
@@ -165,11 +171,16 @@ weston_output_mode_set_native(struct weston_output *output,
 		}
 	}
 
+	old_mode = output->native_mode;
 	output->native_mode = mode;
 	output->native_scale = scale;
 
 	weston_mode_switch_finish(output, mode_changed, scale_changed);
 
+	if (old_mode && (old_mode->width != mode->width))
+		weston_compositor_resize_output(output->compositor, output, mode->width - old_mode->width);
+
+	wl_signal_emit(&output->compositor->output_resized_signal, output);
 	return 0;
 }
 
@@ -4047,23 +4058,22 @@ bind_output(struct wl_client *client,
 		wl_output_send_done(resource);
 }
 
-/* Move other outputs when one is removed so the space remains contiguos. */
+/* Move other outputs when one is resized so the space remains contiguous. */
 static void
-weston_compositor_remove_output(struct weston_compositor *compositor,
-				struct weston_output *remove_output)
+weston_compositor_resize_output(struct weston_compositor *compositor,
+				struct weston_output *resized_output, int delta_width)
 {
 	struct weston_output *output;
-	int offset = 0;
+	bool start_resizing = false;
 
 	wl_list_for_each(output, &compositor->output_list, link) {
-		if (output == remove_output) {
-			offset = output->width;
+		if (output == resized_output) {
+			start_resizing = true;
 			continue;
 		}
 
-		if (offset > 0) {
-			weston_output_move(output,
-					   output->x - offset, output->y);
+		if (start_resizing) {
+			weston_output_move(output, output->x + delta_width, output->y);
 			output->dirty = 1;
 		}
 	}
@@ -4086,7 +4096,7 @@ weston_output_destroy(struct weston_output *output)
 
 	weston_presentation_feedback_discard_list(&output->feedback_list);
 
-	weston_compositor_remove_output(output->compositor, output);
+	weston_compositor_resize_output(output->compositor, output, output->width);
 	wl_list_remove(&output->link);
 
 	wl_signal_emit(&output->compositor->output_destroyed_signal, output);
@@ -4236,7 +4246,7 @@ weston_output_move(struct weston_output *output, int x, int y)
 					output->model,
 					output->transform);
 
-		if (wl_resource_get_version(resource) >= 2)
+		if (wl_resource_get_version(resource) >= WL_OUTPUT_DONE_SINCE_VERSION)
 			wl_output_send_done(resource);
 	}
 }
@@ -4706,6 +4716,7 @@ weston_compositor_create(struct wl_display *display, void *user_data)
 	wl_signal_init(&ec->output_created_signal);
 	wl_signal_init(&ec->output_destroyed_signal);
 	wl_signal_init(&ec->output_moved_signal);
+	wl_signal_init(&ec->output_resized_signal);
 	wl_signal_init(&ec->session_signal);
 	ec->session_active = 1;
 
diff --git a/src/compositor.h b/src/compositor.h
index cb9df00..b71ade0 100644
--- a/src/compositor.h
+++ b/src/compositor.h
@@ -743,6 +743,7 @@ struct weston_compositor {
 	struct wl_signal output_created_signal;
 	struct wl_signal output_destroyed_signal;
 	struct wl_signal output_moved_signal;
+	struct wl_signal output_resized_signal;
 
 	struct wl_signal session_signal;
 	int session_active;
-- 
1.9.1