[gtk+] font chooser: Stop using ::scroll-event

[Matthias Clasen <matthiasc src gnome org>]

commit 7e491fd3fc886370115c47753a69b6fa9acec1e4
Author: Matthias Clasen <mclasen redhat com>
Date:   Mon Jan 1 00:49:38 2018 -0500

    font chooser: Stop using ::scroll-event
    
    We have an event controller for this purpose now.

 gtk/gtkfontchooserwidget.c     |   52 +++++++++++++++++-----------------------
 gtk/ui/gtkfontchooserwidget.ui |    4 ---
 2 files changed, 22 insertions(+), 34 deletions(-)
---
diff --git a/gtk/gtkfontchooserwidget.c b/gtk/gtkfontchooserwidget.c
index 6aff6be..7467c93 100644
--- a/gtk/gtkfontchooserwidget.c
+++ b/gtk/gtkfontchooserwidget.c
@@ -54,6 +54,7 @@
 #include "gtkradiobutton.h"
 #include "gtkcombobox.h"
 #include "gtkgesturemultipress.h"
+#include "gtkeventcontrollerscroll.h"
 
 #if defined(HAVE_HARFBUZZ) && defined(HAVE_PANGOFT)
 #include <pango/pangofc-font.h>
@@ -551,40 +552,19 @@ cursor_changed_cb (GtkTreeView *treeview,
   gtk_delayed_font_description_unref (desc);
 }
 
-static gboolean
-resize_by_scroll_cb (GtkWidget      *scrolled_window,
-                     GdkEventScroll *event,
-                     gpointer        user_data)
+static void
+resize_by_scroll_cb (GtkEventControllerScroll *controller,
+                     double                    dx,
+                     double                    dy,
+                     gpointer                  user_data)
 {
   GtkFontChooserWidget *fc = user_data;
   GtkFontChooserWidgetPrivate *priv = fc->priv;
   GtkAdjustment *adj = gtk_spin_button_get_adjustment (GTK_SPIN_BUTTON (priv->size_spin));
-  GdkScrollDirection direction;
-  gdouble delta_x, delta_y;
-
-  if (!gdk_event_get_scroll_direction ((GdkEvent *) event, &direction))
-    return GDK_EVENT_PROPAGATE;
-
-  gdk_event_get_scroll_deltas ((GdkEvent *) event, &delta_x, &delta_y);
-
-  if (direction == GDK_SCROLL_UP || direction == GDK_SCROLL_RIGHT)
-    gtk_adjustment_set_value (adj,
-                              gtk_adjustment_get_value (adj) +
-                              gtk_adjustment_get_step_increment (adj));
-  else if (direction == GDK_SCROLL_DOWN || direction == GDK_SCROLL_LEFT)
-    gtk_adjustment_set_value (adj,
-                              gtk_adjustment_get_value (adj) -
-                              gtk_adjustment_get_step_increment (adj));
-  else if (direction == GDK_SCROLL_SMOOTH && delta_x != 0.0)
-    gtk_adjustment_set_value (adj,
-                              gtk_adjustment_get_value (adj) +
-                              gtk_adjustment_get_step_increment (adj) * delta_x);
-  else if (direction == GDK_SCROLL_SMOOTH && delta_y != 0.0)
-    gtk_adjustment_set_value (adj,
-                              gtk_adjustment_get_value (adj) -
-                              gtk_adjustment_get_step_increment (adj) * delta_y);
 
-  return TRUE;
+  gtk_adjustment_set_value (adj,
+                            gtk_adjustment_get_value (adj) +
+                            gtk_adjustment_get_step_increment (adj) * dx);
 }
 
 static void
@@ -641,6 +621,16 @@ gtk_font_chooser_widget_map (GtkWidget *widget)
 }
 
 static void
+setup_scroll_resize (GtkWidget            *widget,
+                     GtkFontChooserWidget *fontchooser)
+{
+  GtkEventController *controller;
+
+  controller = gtk_event_controller_scroll_new (widget, GTK_EVENT_CONTROLLER_SCROLL_HORIZONTAL);
+  g_signal_connect (controller, "scroll", G_CALLBACK (resize_by_scroll_cb), fontchooser);
+}
+
+static void
 gtk_font_chooser_widget_measure (GtkWidget       *widget,
                                  GtkOrientation  orientation,
                                  int             for_size,
@@ -748,7 +738,6 @@ gtk_font_chooser_widget_class_init (GtkFontChooserWidgetClass *klass)
   gtk_widget_class_bind_template_callback (widget_class, cursor_changed_cb);
   gtk_widget_class_bind_template_callback (widget_class, row_activated_cb);
   gtk_widget_class_bind_template_callback (widget_class, gtk_font_chooser_widget_set_cell_size);
-  gtk_widget_class_bind_template_callback (widget_class, resize_by_scroll_cb);
   gtk_widget_class_bind_template_callback (widget_class, rows_changed_cb);
   gtk_widget_class_bind_template_callback (widget_class, size_change_cb);
   gtk_widget_class_bind_template_callback (widget_class, output_cb);
@@ -872,6 +861,9 @@ gtk_font_chooser_widget_init (GtkFontChooserWidget *fontchooser)
                                            fontchooser,
                                            NULL);
 
+  setup_scroll_resize (priv->preview, fontchooser);
+  setup_scroll_resize (priv->size_slider, fontchooser);
+
   priv->tweak_action = G_ACTION (g_simple_action_new_stateful ("tweak", NULL, g_variant_new_boolean 
(FALSE)));
   g_signal_connect (priv->tweak_action, "change-state", G_CALLBACK (change_tweak), fontchooser);
 
diff --git a/gtk/ui/gtkfontchooserwidget.ui b/gtk/ui/gtkfontchooserwidget.ui
index 4972a81..b5c80b3 100644
--- a/gtk/ui/gtkfontchooserwidget.ui
+++ b/gtk/ui/gtkfontchooserwidget.ui
@@ -111,7 +111,6 @@
                       <object class="GtkEntry" id="preview">
                         <property name="can-focus">1</property>
                         <property name="placeholder-text" translatable="yes">Preview text</property>
-                        <signal name="scroll-event" handler="resize_by_scroll_cb" swapped="no"/>
                       </object>
                       <packing>
                         <property name="left-attach">0</property>
@@ -137,7 +136,6 @@
                         <property name="adjustment">slider_adjustment</property>
                         <property name="draw-value">0</property>
                         <property name="round-digits">0</property>
-                        <signal name="scroll-event" handler="resize_by_scroll_cb" swapped="no"/>
                       </object>
                       <packing>
                         <property name="left-attach">1</property>
@@ -229,7 +227,6 @@
                 <property name="placeholder-text" translatable="yes">Preview text</property>
                 <property name="text" bind-source="preview" bind-property="text" bind-flags="bidirectional"/>
                 <property name="attributes" bind-source="preview" bind-property="attributes" 
bind-flags="bidirectional"/>
-                <signal name="scroll-event" handler="resize_by_scroll_cb" swapped="no"/>
               </object>
             </child>
             <child>
@@ -267,7 +264,6 @@
                             <property name="adjustment">slider_adjustment</property>
                             <property name="draw-value">0</property>
                             <property name="round-digits">0</property>
-                            <signal name="scroll-event" handler="resize_by_scroll_cb" swapped="no"/>
                           </object>
                           <packing>
                             <property name="left-attach">1</property>