]> Pileus Git - ~andy/gtk/blobdiff - gtk/gtkwidget.c
Clean up the opacity handling
[~andy/gtk] / gtk / gtkwidget.c
index 585b4f873efb6d254387f25249ae53c69214dc6c..7bbd4faa30731a577961a70aff02773c1d7cf50f 100644 (file)
@@ -27,6 +27,7 @@
 #include <stdarg.h>
 #include <string.h>
 #include <locale.h>
+#include <math.h>
 
 #include <gobject/gvaluecollector.h>
 #include <gobject/gobjectnotifyqueue.c>
@@ -36,6 +37,7 @@
 #include "gtkaccelmapprivate.h"
 #include "gtkclipboard.h"
 #include "gtkcssstylepropertyprivate.h"
+#include "gtkcssnumbervalueprivate.h"
 #include "gtkiconfactory.h"
 #include "gtkintl.h"
 #include "gtkmarshalers.h"
  *   </accessibility>
  *   <child internal-child="accessible">
  *     <object class="AtkObject" id="a11y-button1">
- *       <property name="AtkObject::name">Clickable Button</property>
+ *       <property name="accessible-name">Clickable Button</property>
  *     </object>
  *   </child>
  * </object>
@@ -357,6 +359,12 @@ struct _GtkWidgetPrivate
   /* SizeGroup related flags */
   guint have_size_groups      : 1;
 
+  guint norender_children     : 1;
+  guint norender              : 1; /* Don't expose windows, instead recurse via draw */
+
+  guint8 alpha;
+  guint8 user_alpha;
+
   /* The widget's name. If the widget does not have a name
    * (the name is NULL), then its name (as returned by
    * "gtk_widget_get_name") is its class's name.
@@ -395,6 +403,7 @@ struct _GtkWidgetPrivate
    * GTK_NO_WINDOW flag being set).
    */
   GdkWindow *window;
+  GList *registered_windows;
 
   /* The widget's parent */
   GtkWidget *parent;
@@ -507,6 +516,7 @@ enum {
   PROP_TOOLTIP_MARKUP,
   PROP_TOOLTIP_TEXT,
   PROP_WINDOW,
+  PROP_OPACITY,
   PROP_DOUBLE_BUFFERED,
   PROP_HALIGN,
   PROP_VALIGN,
@@ -602,7 +612,8 @@ static PangoContext*        gtk_widget_peek_pango_context           (GtkWidget        *widget);
 static void            gtk_widget_update_pango_context         (GtkWidget        *widget);
 static void            gtk_widget_propagate_state              (GtkWidget        *widget,
                                                                 GtkStateData     *data);
-;
+static void             gtk_widget_update_alpha                 (GtkWidget        *widget);
+
 static gint            gtk_widget_event_internal               (GtkWidget        *widget,
                                                                 GdkEvent         *event);
 static gboolean                gtk_widget_real_mnemonic_activate       (GtkWidget        *widget,
@@ -699,6 +710,9 @@ static void gtk_widget_set_device_enabled_internal (GtkWidget *widget,
                                                     gboolean   recurse,
                                                     gboolean   enabled);
 static gboolean event_window_is_still_viewable (GdkEvent *event);
+static void gtk_cairo_set_event (cairo_t        *cr,
+                                GdkEventExpose *event);
+static void gtk_widget_propagate_alpha (GtkWidget *widget);
 
 /* --- variables --- */
 static gpointer         gtk_widget_parent_class = NULL;
@@ -808,9 +822,23 @@ gtk_widget_draw_marshaller (GClosure     *closure,
                             gpointer      invocation_hint,
                             gpointer      marshal_data)
 {
+  GtkWidget *widget = g_value_get_object (&param_values[0]);
+  GdkEventExpose *tmp_event;
+  gboolean push_group;
   cairo_t *cr = g_value_get_boxed (&param_values[1]);
 
   cairo_save (cr);
+  tmp_event = _gtk_cairo_get_event (cr);
+
+  push_group =
+    widget->priv->alpha != 255 &&
+    (!gtk_widget_get_has_window (widget) || tmp_event == NULL);
+
+  if (push_group)
+    {
+      cairo_push_group (cr);
+      gtk_cairo_set_event (cr, NULL);
+    }
 
   _gtk_marshal_BOOLEAN__BOXED (closure,
                                return_value,
@@ -819,6 +847,15 @@ gtk_widget_draw_marshaller (GClosure     *closure,
                                invocation_hint,
                                marshal_data);
 
+
+  if (push_group)
+    {
+      cairo_pop_group_to_source (cr);
+      cairo_set_operator (cr, CAIRO_OPERATOR_OVER);
+      cairo_paint_with_alpha (cr, widget->priv->alpha / 255.0);
+    }
+
+  gtk_cairo_set_event (cr, tmp_event);
   cairo_restore (cr);
 }
 
@@ -831,6 +868,9 @@ gtk_widget_draw_marshallerv (GClosure     *closure,
                             int           n_params,
                             GType        *param_types)
 {
+  GtkWidget *widget = GTK_WIDGET (instance);
+  GdkEventExpose *tmp_event;
+  gboolean push_group;
   cairo_t *cr;
   va_list args_copy;
 
@@ -838,6 +878,17 @@ gtk_widget_draw_marshallerv (GClosure     *closure,
   cr = va_arg (args_copy, gpointer);
 
   cairo_save (cr);
+  tmp_event = _gtk_cairo_get_event (cr);
+
+  push_group =
+    widget->priv->alpha != 255 &&
+    (!gtk_widget_get_has_window (widget) || tmp_event == NULL);
+
+  if (push_group)
+    {
+      cairo_push_group (cr);
+      gtk_cairo_set_event (cr, NULL);
+    }
 
   _gtk_marshal_BOOLEAN__BOXEDv (closure,
                                return_value,
@@ -847,6 +898,15 @@ gtk_widget_draw_marshallerv (GClosure     *closure,
                                n_params,
                                param_types);
 
+
+  if (push_group)
+    {
+      cairo_pop_group_to_source (cr);
+      cairo_set_operator (cr, CAIRO_OPERATOR_OVER);
+      cairo_paint_with_alpha (cr, widget->priv->alpha / 255.0);
+    }
+
+  gtk_cairo_set_event (cr, tmp_event);
   cairo_restore (cr);
 
   va_end (args_copy);
@@ -1419,6 +1479,25 @@ gtk_widget_class_init (GtkWidgetClass *klass)
                                                          FALSE,
                                                          GTK_PARAM_READWRITE));
 
+  /**
+   * GtkWidget:opacity:
+   *
+   * The requested opacity of the widget. See gtk_widget_set_opacity() for
+   * more details about window opacity.
+   *
+   * Before 3.8 this was only availible in GtkWindow
+   *
+   * Since: 3.8
+   */
+  g_object_class_install_property (gobject_class,
+                                  PROP_OPACITY,
+                                  g_param_spec_double ("opacity",
+                                                       P_("Opacity for Widget"),
+                                                       P_("The opacity of the widget, from 0 to 1"),
+                                                       0.0,
+                                                       1.0,
+                                                       1.0,
+                                                       GTK_PARAM_READWRITE));
   /**
    * GtkWidget::show:
    * @widget: the object which received the signal.
@@ -3483,6 +3562,9 @@ gtk_widget_set_property (GObject         *object,
       gtk_widget_set_vexpand (widget, g_value_get_boolean (value));
       g_object_thaw_notify (G_OBJECT (widget));
       break;
+    case PROP_OPACITY:
+      gtk_widget_set_opacity (widget, g_value_get_double (value));
+      break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -3639,6 +3721,9 @@ gtk_widget_get_property (GObject         *object,
                            gtk_widget_get_hexpand (widget) &&
                            gtk_widget_get_vexpand (widget));
       break;
+    case PROP_OPACITY:
+      g_value_set_double (value, gtk_widget_get_opacity (widget));
+      break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -3661,6 +3746,8 @@ gtk_widget_init (GtkWidget *widget)
   priv->allocation.y = -1;
   priv->allocation.width = 1;
   priv->allocation.height = 1;
+  priv->user_alpha = 255;
+  priv->alpha = 255;
   priv->window = NULL;
   priv->parent = NULL;
 
@@ -3951,6 +4038,8 @@ gtk_widget_unparent (GtkWidget *widget)
     g_object_notify_queue_clear (G_OBJECT (widget), nqueue);
   g_object_notify_queue_thaw (G_OBJECT (widget), nqueue);
 
+  gtk_widget_propagate_alpha (widget);
+
   gtk_widget_pop_verify_invariants (widget);
   g_object_unref (widget);
 }
@@ -6716,6 +6805,7 @@ gtk_widget_real_style_updated (GtkWidget *widget)
   GtkWidgetPrivate *priv = widget->priv;
 
   gtk_widget_update_pango_context (widget);
+  gtk_widget_update_alpha (widget);
 
   if (priv->style != NULL &&
       priv->style != gtk_widget_get_default_style ())
@@ -8078,6 +8168,8 @@ gtk_widget_set_parent (GtkWidget *widget,
       gtk_widget_queue_compute_expand (parent);
     }
 
+  gtk_widget_propagate_alpha (widget);
+
   gtk_widget_pop_verify_invariants (widget);
 }
 
@@ -10536,7 +10628,7 @@ gtk_widget_real_unrealize (GtkWidget *widget)
 
   if (gtk_widget_get_has_window (widget))
     {
-      gdk_window_set_user_data (priv->window, NULL);
+      gtk_widget_unregister_window (widget, priv->window);
       gdk_window_destroy (priv->window);
       priv->window = NULL;
     }
@@ -13526,7 +13618,7 @@ gtk_widget_set_allocation (GtkWidget           *widget,
   GtkWidgetPrivate *priv;
 
   g_return_if_fail (GTK_IS_WIDGET (widget));
-  g_return_if_fail (gtk_widget_get_visible (widget));
+  g_return_if_fail (gtk_widget_get_visible (widget) || gtk_widget_is_toplevel (widget));
   g_return_if_fail (allocation != NULL);
 
   priv = widget->priv;
@@ -13633,10 +13725,83 @@ gtk_widget_set_window (GtkWidget *widget,
   if (priv->window != window)
     {
       priv->window = window;
+
+      if (gtk_widget_get_has_window (widget) && window != NULL && !gdk_window_has_native (window))
+       gdk_window_set_opacity (window,
+                               priv->norender ? 0 : priv->alpha / 255.0);
+
       g_object_notify (G_OBJECT (widget), "window");
     }
 }
 
+/**
+ * gtk_widget_register_window:
+ * @widget: a #GtkWidget
+ * @window: a #GdkWindow
+ *
+ * Registers a #GdkWindow with the widget and sets it up so that
+ * the widget recieves events for it. Call gtk_widget_unregister_window()
+ * when destroying the window.
+ *
+ * Before 3.8 you needed to call gdk_window_set_user_data() directly to set
+ * this up. This is now deprecated and you should use gtk_widget_register_window()
+ * instead. Old code will keep working as is, although some new features like
+ * transparency might not work perfectly.
+ *
+ * Since: 3.8
+ */
+void
+gtk_widget_register_window (GtkWidget    *widget,
+                           GdkWindow    *window)
+{
+  GtkWidgetPrivate *priv;
+  gpointer user_data;
+
+  g_return_if_fail (GTK_IS_WIDGET (widget));
+  g_return_if_fail (GDK_IS_WINDOW (window));
+
+  gdk_window_get_user_data (window, &user_data);
+  g_assert (user_data == NULL);
+
+  priv = widget->priv;
+
+  gdk_window_set_user_data (window, widget);
+  priv->registered_windows = g_list_prepend (priv->registered_windows, window);
+
+  if (!gtk_widget_get_has_window (widget) && !gdk_window_has_native (window))
+    gdk_window_set_opacity (window,
+                           priv->norender_children ? 0.0 : 1.0);
+}
+
+/**
+ * gtk_widget_unregister_window:
+ * @widget: a #GtkWidget
+ * @window: a #GdkWindow
+ *
+ * Unregisters a #GdkWindow from the widget that was previously set up with
+ * gtk_widget_register_window(). You need to call this when the window is
+ * no longer used by the widget, such as when you destroy it.
+ *
+ * Since: 3.8
+ */
+void
+gtk_widget_unregister_window (GtkWidget    *widget,
+                             GdkWindow    *window)
+{
+  GtkWidgetPrivate *priv;
+  gpointer user_data;
+
+  g_return_if_fail (GTK_IS_WIDGET (widget));
+  g_return_if_fail (GDK_IS_WINDOW (window));
+
+  priv = widget->priv;
+
+  gdk_window_get_user_data (window, &user_data);
+  g_assert (user_data == widget);
+  gdk_window_set_user_data (window, NULL);
+  priv->registered_windows = g_list_remove (priv->registered_windows, window);
+}
+
 /**
  * gtk_widget_get_window:
  * @widget: a #GtkWidget
@@ -13699,6 +13864,177 @@ gtk_widget_set_support_multidevice (GtkWidget *widget,
     gdk_window_set_support_multidevice (priv->window, support_multidevice);
 }
 
+/* There are multiple alpha related sources, the user can specify alpha
+ * in gtk_widget_set_opacity, secondly we can get it from the css opacity. These two
+ * are multiplied together to form the total alpha.
+ *
+ * We handle opacity in two ways. For a windowed widget, with opacity set but no opacity
+ * group we directly set the opacity of widget->window. This will cause gdk to properly
+ * redirect drawing inside the window to a buffer and do OVER paint_with_alpha.
+ *
+ * However, if the widget is not windowed,
+ * we do the opacity handling in the ::draw marshaller for the widget. A naive
+ * implementation of this would break for windowed widgets or descendant widgets with
+ * windows, as these would not be handled by the ::draw signal. To handle this we set
+ * all such gdkwindows as fully transparent and then override gtk_cairo_should_draw_window()
+ * to make the draw signal propagate to *all* child widgets/windows.
+ *
+ * Note: We don't make all child windows fully transparent, we stop at the first one
+ * in each branch when propagating down the hierarchy.
+ */
+
+
+/* This is called when priv->alpha changes, and should
+ * update priv->norender and GdkWindow opacity for this widget and any children that
+ * needs changing. It is also called whenver the parent changes, the parents
+ * norender_children state changes, or the has_window state of the widget changes.
+ */
+static void
+gtk_widget_propagate_alpha (GtkWidget *widget)
+{
+  GtkWidgetPrivate *priv = widget->priv;
+  GtkWidget *parent;
+  gboolean norender, norender_children;
+  GList *l;
+
+  parent = priv->parent;
+
+  norender =
+    /* If the parent has norender_children, propagate that here */
+    (parent != NULL && parent->priv->norender_children);
+
+  /* Windowed widget children should norender if: */
+  norender_children =
+    /* The widget is no_window (otherwise its enought to mark it norender/alpha), and */
+    !gtk_widget_get_has_window (widget) &&
+     ( /* norender is set, or */
+      norender ||
+      /* widget has an alpha */
+      priv->alpha != 255
+       );
+
+  if (gtk_widget_get_has_window (widget))
+    {
+      if (priv->window != NULL && !gdk_window_has_native (priv->window))
+       gdk_window_set_opacity (priv->window,
+                               norender ? 0 : priv->alpha / 255.0);
+    }
+  else /* !has_window */
+    {
+      for (l = priv->registered_windows; l != NULL; l = l->next)
+       {
+         GdkWindow *w = l->data;
+         if (!gdk_window_has_native (w))
+           gdk_window_set_opacity (w, norender_children ? 0.0 : 1.0);
+       }
+    }
+
+  priv->norender = norender;
+  if (priv->norender_children != norender_children)
+    {
+      priv->norender_children = norender_children;
+
+      if (GTK_IS_CONTAINER (widget))
+       gtk_container_forall (GTK_CONTAINER (widget), (GtkCallback)gtk_widget_propagate_alpha, NULL);
+    }
+
+  if (gtk_widget_get_realized (widget))
+    gtk_widget_queue_draw (widget);
+}
+
+static void
+gtk_widget_update_alpha (GtkWidget *widget)
+{
+  GtkWidgetPrivate *priv;
+  double opacity;
+  guint8 alpha;
+
+  priv = widget->priv;
+
+  alpha = priv->user_alpha;
+
+  if (priv->context)
+    {
+      opacity =
+       _gtk_css_number_value_get (_gtk_style_context_peek_property (priv->context,
+                                                                    GTK_CSS_PROPERTY_OPACITY),
+                                  100);
+      opacity = CLAMP (opacity, 0.0, 1.0);
+      alpha = round (priv->user_alpha * opacity);
+    }
+
+  if (alpha == priv->alpha)
+    return;
+
+  priv->alpha = alpha;
+
+  gtk_widget_propagate_alpha (widget);
+
+}
+
+/**
+ * gtk_widget_set_opacity:
+ * @widget: a #GtkWidget
+ * @opacity: desired opacity, between 0 and 1
+ *
+ * Request the @widget to be rendered partially transparent,
+ * with opacity 0 being fully transparent and 1 fully opaque. (Opacity values
+ * are clamped to the [0,1] range.).
+ * This works on both toplevel widget, and child widgets, although there
+ * are some limitations:
+ *
+ * For toplevel widgets this depends on the capabilities of the windowing
+ * system. On X11 this has any effect only on X screens with a compositing manager
+ * running. See gtk_widget_is_composited(). On Windows it should work
+ * always, although setting a window's opacity after the window has been
+ * shown causes it to flicker once on Windows.
+ *
+ * For child widgets it doesn't work if any affected widget has a native window, or
+ * disables double buffering.
+ *
+ * Since: 3.8
+ **/
+void
+gtk_widget_set_opacity  (GtkWidget *widget,
+                        gdouble    opacity)
+{
+  GtkWidgetPrivate *priv;
+  guint8 alpha;
+
+  g_return_if_fail (GTK_IS_WIDGET (widget));
+
+  priv = widget->priv;
+
+  opacity = CLAMP (opacity, 0.0, 1.0);
+
+  alpha = round (opacity * 255);
+  if (alpha == priv->user_alpha)
+    return;
+
+  priv->user_alpha = alpha;
+
+  gtk_widget_update_alpha (widget);
+}
+
+/**
+ * gtk_widget_get_opacity:
+ * @widget: a #GtkWidget
+ *
+ * Fetches the requested opacity for this widget. See
+ * gtk_widget_set_opacity().
+ *
+ * Return value: the requested opacity for this widget.
+ *
+ * Since: 3.8
+ **/
+gdouble
+gtk_widget_get_opacity (GtkWidget *widget)
+{
+  g_return_val_if_fail (GTK_IS_WIDGET (widget), 0.0);
+
+  return widget->priv->alpha / 255.0;
+}
+
 static void
 _gtk_widget_set_has_focus (GtkWidget *widget,
                            gboolean   has_focus)