[gnome-terminal] window: Support animated and touch scrolling

[Christian Persch <chpe src gnome org>]

commit 0dd655c569f8b8141216be8e921cb5d1dcb53b6e
Author: Debarshi Ray <debarshir gnome org>
Date:   Mon Aug 1 19:33:57 2016 +0200

    window: Support animated and touch scrolling
    
    Add back code to conditionally compile TerminalScreenContainer
    to use a GtkScrolledWindow instead of creating our own GtkScrollbar.
    When used, this gives us animated and touch scrolling for free.
    We can mimic the existing behaviour by creating a GtkScrolledWindow
    that never scrolls horizontally, but always vertically. We can
    use the new EXTERNAL policy to hide the vertical scrollbar widget
    depending on the setting.
    
    However, GtkScrolledWindow doesn't work with
    GTK_SIZE_REQUEST_CONSTANT_SIZE children, so this code will only
    exist for development purposes until gtk+ fixes this.
    
    Also install custom CSS to hide GtkScrolledWindow over/underscroll
    animations.
    
    Also reverts commit 41eb2ec73653adc5fd36fa73cebdc8a6169f8516
    
    https://bugzilla.gnome.org/show_bug.cgi?id=733210

 src/terminal-screen-container.c |   60 ++++++++++++++++++++++++++++++++++++--
 src/terminal.common.css         |    8 +++++
 src/terminal.gresource.xml      |    2 +-
 3 files changed, 65 insertions(+), 5 deletions(-)
---
diff --git a/src/terminal-screen-container.c b/src/terminal-screen-container.c
index 1864712..a032fe7 100644
--- a/src/terminal-screen-container.c
+++ b/src/terminal-screen-container.c
@@ -20,6 +20,10 @@
 #include "terminal-screen-container.h"
 #include "terminal-debug.h"
 
+#if 0
+#define USE_SCROLLED_WINDOW
+#endif
+
 #include <gtk/gtk.h>
 
 #define TERMINAL_SCREEN_CONTAINER_GET_PRIVATE(screen_container)(G_TYPE_INSTANCE_GET_PRIVATE 
((screen_container), TERMINAL_TYPE_SCREEN_CONTAINER, TerminalScreenContainerPrivate))
@@ -27,8 +31,12 @@
 struct _TerminalScreenContainerPrivate
 {
   TerminalScreen *screen;
+#ifdef USE_SCROLLED_WINDOW
+  GtkWidget *scrolled_window;
+#else
   GtkWidget *hbox;
   GtkWidget *vscrollbar;
+#endif
   GtkPolicyType hscrollbar_policy;
   GtkPolicyType vscrollbar_policy;
 };
@@ -38,9 +46,7 @@ enum
   PROP_0,
   PROP_SCREEN,
   PROP_HSCROLLBAR_POLICY,
-  PROP_VSCROLLBAR_POLICY,
-  PROP_WINDOW_PLACEMENT,
-  PROP_WINDOW_PLACEMENT_SET
+  PROP_VSCROLLBAR_POLICY
 };
 
 G_DEFINE_TYPE (TerminalScreenContainer, terminal_screen_container, GTK_TYPE_OVERLAY)
@@ -49,13 +55,15 @@ G_DEFINE_TYPE (TerminalScreenContainer, terminal_screen_container, GTK_TYPE_OVER
 
 /* Widget class implementation */
 
+#ifndef USE_SCROLLED_WINDOW
+
 static void
 terminal_screen_container_style_updated (GtkWidget *widget)
 {
   TerminalScreenContainer *container = TERMINAL_SCREEN_CONTAINER (widget);
   TerminalScreenContainerPrivate *priv = container->priv;
   GtkCornerType corner;
-  gboolean set;  
+  gboolean set;
 
   GTK_WIDGET_CLASS (terminal_screen_container_parent_class)->style_updated (widget);
 
@@ -84,6 +92,8 @@ terminal_screen_container_style_updated (GtkWidget *widget)
   }
 }
 
+#endif /* !USE_SCROLLED_WINDOW */
+
 /* Class implementation */
 
 static void
@@ -107,6 +117,25 @@ terminal_screen_container_constructed (GObject *object)
 
   g_assert (priv->screen != NULL);
 
+#ifdef USE_SCROLLED_WINDOW
+{
+  GtkAdjustment *hadjustment;
+  GtkAdjustment *vadjustment;
+
+  hadjustment = gtk_scrollable_get_hadjustment (GTK_SCROLLABLE (priv->screen));
+  vadjustment = gtk_scrollable_get_vadjustment (GTK_SCROLLABLE (priv->screen));
+
+  priv->scrolled_window = gtk_scrolled_window_new (hadjustment, vadjustment);
+  gtk_scrolled_window_set_overlay_scrolling (GTK_SCROLLED_WINDOW (priv->scrolled_window), FALSE);
+  gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (priv->scrolled_window),
+                                  priv->hscrollbar_policy,
+                                  priv->vscrollbar_policy);
+  gtk_container_add (GTK_CONTAINER (priv->scrolled_window), GTK_WIDGET (priv->screen));
+
+  gtk_container_add (GTK_CONTAINER (container), priv->scrolled_window);
+  gtk_widget_show_all (priv->scrolled_window);
+}
+#else
   priv->hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
 
   priv->vscrollbar = gtk_scrollbar_new (GTK_ORIENTATION_VERTICAL,
@@ -117,6 +146,7 @@ terminal_screen_container_constructed (GObject *object)
 
   gtk_container_add (GTK_CONTAINER (container), priv->hbox);
   gtk_widget_show_all (priv->hbox);
+#endif
 
   _terminal_screen_update_scrollbar (priv->screen);
 }
@@ -178,7 +208,9 @@ static void
 terminal_screen_container_class_init (TerminalScreenContainerClass *klass)
 {
   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
+#ifndef USE_SCROLLED_WINDOW
   GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
+#endif
 
   g_type_class_add_private (gobject_class, sizeof (TerminalScreenContainerPrivate));
 
@@ -186,7 +218,9 @@ terminal_screen_container_class_init (TerminalScreenContainerClass *klass)
   gobject_class->get_property = terminal_screen_container_get_property;
   gobject_class->set_property = terminal_screen_container_set_property;
 
+#ifndef USE_SCROLLED_WINDOW
   widget_class->style_updated = terminal_screen_container_style_updated;
+#endif
 
   g_object_class_install_property
     (gobject_class,
@@ -214,6 +248,7 @@ terminal_screen_container_class_init (TerminalScreenContainerClass *klass)
                         G_PARAM_READWRITE |
                         G_PARAM_STATIC_STRINGS));
 
+#ifndef USE_SCROLLED_WINDOW
    gtk_widget_class_install_style_property (widget_class,
                                             g_param_spec_enum ("window-placement", NULL, NULL,
                                                                GTK_TYPE_CORNER_TYPE,
@@ -225,6 +260,7 @@ terminal_screen_container_class_init (TerminalScreenContainerClass *klass)
                                                                  FALSE,
                                                                  G_PARAM_READWRITE |
                                                                  G_PARAM_STATIC_STRINGS));
+#endif
 }
 
 /* public API */
@@ -309,6 +345,21 @@ terminal_screen_container_set_policy (TerminalScreenContainer *container,
     g_object_notify (object, "vscrollbar-policy");
   }
 
+#ifdef USE_SCROLLED_WINDOW
+  switch (vpolicy) {
+  case GTK_POLICY_NEVER:
+    vpolicy = GTK_POLICY_EXTERNAL;
+    break;
+  case GTK_POLICY_AUTOMATIC:
+  case GTK_POLICY_ALWAYS:
+    vpolicy = GTK_POLICY_ALWAYS;
+    break;
+  default:
+    g_assert_not_reached ();
+  }
+
+  gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (priv->scrolled_window), hpolicy, vpolicy);
+#else
   switch (vpolicy) {
     case GTK_POLICY_NEVER:
       gtk_widget_hide (priv->vscrollbar);
@@ -320,6 +371,7 @@ terminal_screen_container_set_policy (TerminalScreenContainer *container,
     default:
       g_assert_not_reached ();
   }
+#endif /* USE_SCROLLED_WINDOW */
 
   g_object_thaw_notify (object);
 }
diff --git a/src/terminal.common.css b/src/terminal.common.css
index 9ac6ed5..1d4d41f 100644
--- a/src/terminal.common.css
+++ b/src/terminal.common.css
@@ -1 +1,9 @@
 /* Generic theme-independent CSS file */
+
+terminal-window scrolledwindow undershoot.top,
+terminal-window scrolledwindow undershoot.bottom,
+terminal-window scrolledwindow overshoot.top,
+terminal-window scrolledwindow overshoot.bottom
+{
+  background: none;
+}
diff --git a/src/terminal.gresource.xml b/src/terminal.gresource.xml
index 6be1a1c..9638b5b 100644
--- a/src/terminal.gresource.xml
+++ b/src/terminal.gresource.xml
@@ -24,6 +24,6 @@
     <file alias="ui/profile-preferences.ui" compressed="true" 
preprocess="xml-stripblanks">profile-preferences.ui</file>
     <file alias="ui/window.ui" compressed="true" preprocess="xml-stripblanks">terminal-window.ui</file>
     <file alias="gtk/menus.ui" compressed="true" preprocess="xml-stripblanks">terminal-menus.ui</file>
-    <!-- <file alias="css/terminal.css" compressed="true">terminal.common.css</file> -->
+    <file alias="css/terminal.css" compressed="true">terminal.common.css</file>
   </gresource>
 </gresources>