[gtk/wip/otte/widgetfactory-dnd: 4/7] widget-factory: Add images that support dnd

[Benjamin Otte <otte src gnome org>]

commit bb87cffaac5140819f50f1f6e8e77e0cdef540b7
Author: Benjamin Otte <otte redhat com>
Date:   Mon Jul 26 02:35:09 2021 +0200

    widget-factory: Add images that support dnd
    
    Just use the bottom left notebook for a GtkPicture with custom drag
    source and drop target.

 demos/widget-factory/widget-factory.c  | 33 +++++++++++++++++++++
 demos/widget-factory/widget-factory.ui | 54 +++++++++++++++++++++++++++++-----
 2 files changed, 79 insertions(+), 8 deletions(-)
---
diff --git a/demos/widget-factory/widget-factory.c b/demos/widget-factory/widget-factory.c
index 5b10ecdd74..7d49469fe1 100644
--- a/demos/widget-factory/widget-factory.c
+++ b/demos/widget-factory/widget-factory.c
@@ -696,6 +696,37 @@ on_range_to_changed (GtkSpinButton *to)
     gtk_spin_button_set_value (from, v2);
 }
 
+static GdkContentProvider *
+on_picture_drag_prepare (GtkDragSource *source,
+                         double         x,
+                         double         y,
+                         gpointer       unused)
+{
+  GtkWidget *picture;
+
+  picture = gtk_event_controller_get_widget (GTK_EVENT_CONTROLLER (source));
+
+  return gdk_content_provider_new_typed (GDK_TYPE_TEXTURE, gtk_picture_get_paintable (GTK_PICTURE 
(picture)));
+}
+
+static gboolean
+on_picture_drop (GtkDropTarget *dest,
+                 const GValue  *value,
+                 double         x,
+                 double         y,
+                 gpointer       unused)
+{
+  GtkWidget *picture;
+  GdkPaintable *paintable;
+
+  picture = gtk_event_controller_get_widget (GTK_EVENT_CONTROLLER (dest));
+  paintable = g_value_get_object (value);
+
+  gtk_picture_set_paintable (GTK_PICTURE (picture), paintable);
+
+  return TRUE;
+}
+
 static void
 info_bar_response (GtkWidget *infobar, int response_id)
 {
@@ -2040,6 +2071,8 @@ activate (GApplication *app)
           "on_page_combo_changed", (GCallback)on_page_combo_changed,
           "on_range_from_changed", (GCallback)on_range_from_changed,
           "on_range_to_changed", (GCallback)on_range_to_changed,
+          "on_picture_drag_prepare", (GCallback)on_picture_drag_prepare,
+          "on_picture_drop", (GCallback)on_picture_drop,
           "tab_close_cb", (GCallback)tab_close_cb,
           "increase_icon_size", (GCallback)increase_icon_size,
           "decrease_icon_size", (GCallback)decrease_icon_size,
diff --git a/demos/widget-factory/widget-factory.ui b/demos/widget-factory/widget-factory.ui
index c37ade2945..684d5011a1 100644
--- a/demos/widget-factory/widget-factory.ui
+++ b/demos/widget-factory/widget-factory.ui
@@ -1251,8 +1251,21 @@ Suspendisse feugiat quam quis dolor accumsan cursus.</property>
                             <child>
                               <object class="GtkNotebookPage">
                                 <property name="child">
-                                  <object class="GtkBox" id="box6">
-                                    <property name="orientation">vertical</property>
+                                  <object class="GtkPicture">
+                                    <property 
name="file">resource:///org/gtk/WidgetFactory4/sunset.jpg</property>
+                                    <child>
+                                      <object class="GtkDragSource">
+                                        <property name="actions">copy</property>
+                                        <signal name="prepare" handler="on_picture_drag_prepare" 
swapped="no"/>
+                                      </object>
+                                    </child>
+                                    <child>
+                                      <object class="GtkDropTarget">
+                                        <property name="actions">copy</property>
+                                        <property name="formats">GdkTexture</property>
+                                        <signal name="drop" handler="on_picture_drop" swapped="no"/>
+                                      </object>
+                                    </child>
                                   </object>
                                 </property>
                                 <property name="tab">
@@ -1265,8 +1278,21 @@ Suspendisse feugiat quam quis dolor accumsan cursus.</property>
                             <child>
                               <object class="GtkNotebookPage">
                                 <property name="child">
-                                  <object class="GtkBox" id="box7">
-                                    <property name="orientation">vertical</property>
+                                  <object class="GtkPicture">
+                                    <property 
name="file">resource:///org/gtk/WidgetFactory4/sunset.jpg</property>
+                                    <child>
+                                      <object class="GtkDragSource">
+                                        <property name="actions">copy</property>
+                                        <signal name="prepare" handler="on_picture_drag_prepare" 
swapped="no"/>
+                                      </object>
+                                    </child>
+                                    <child>
+                                      <object class="GtkDropTarget">
+                                        <property name="actions">copy</property>
+                                        <property name="formats">GdkTexture</property>
+                                        <signal name="drop" handler="on_picture_drop" swapped="no"/>
+                                      </object>
+                                    </child>
                                   </object>
                                 </property>
                                 <property name="tab">
@@ -1278,10 +1304,22 @@ Suspendisse feugiat quam quis dolor accumsan cursus.</property>
                             </child>
                             <child>
                               <object class="GtkNotebookPage">
-                                <property name="position">2</property>
                                 <property name="child">
-                                  <object class="GtkBox" id="box8">
-                                    <property name="orientation">vertical</property>
+                                  <object class="GtkPicture">
+                                    <property 
name="file">resource:///org/gtk/WidgetFactory4/sunset.jpg</property>
+                                    <child>
+                                      <object class="GtkDragSource">
+                                        <property name="actions">copy</property>
+                                        <signal name="prepare" handler="on_picture_drag_prepare" 
swapped="no"/>
+                                      </object>
+                                    </child>
+                                    <child>
+                                      <object class="GtkDropTarget">
+                                        <property name="actions">copy</property>
+                                        <property name="formats">GdkTexture</property>
+                                        <signal name="drop" handler="on_picture_drop" swapped="no"/>
+                                      </object>
+                                    </child>
                                   </object>
                                 </property>
                                 <property name="tab">
@@ -1299,7 +1337,7 @@ Suspendisse feugiat quam quis dolor accumsan cursus.</property>
                             <child>
                               <object class="GtkNotebookPage">
                                 <property name="child">
-                                  <object class="GtkBox" id="box9">
+                                  <object class="GtkBox" id="box8">
                                     <property name="orientation">vertical</property>
                                   </object>
                                 </property>