[gimp] libgimpwidgets: handle Enter/Esc keys in GimpSpinButton

[Ell <ell src gnome org>]

commit e5310230317854ecd5399f6db6de38d08dea8f3b
Author: Ell <ell_se yahoo com>
Date:   Tue Jul 14 12:50:04 2020 +0300

    libgimpwidgets: handle Enter/Esc keys in GimpSpinButton
    
    In GimpSpinButton, don't propagate Enter key-press events if
    updating the spin-button's value in response changes the entered
    text.  This prevents confirming dialogs when hitting Enter after
    entering a math expression in size entries, updating their value
    instead.
    
    Likewise, don't propagate Escape key-press events if a new value
    was entered, and restore the original value instead.

 libgimpwidgets/gimpspinbutton.c | 52 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)
---
diff --git a/libgimpwidgets/gimpspinbutton.c b/libgimpwidgets/gimpspinbutton.c
index 115d0585de..7abd79a62e 100644
--- a/libgimpwidgets/gimpspinbutton.c
+++ b/libgimpwidgets/gimpspinbutton.c
@@ -21,8 +21,11 @@
 
 #include "config.h"
 
+#include <string.h>
+
 #include <gegl.h>
 #include <gtk/gtk.h>
+#include <gdk/gdkkeysyms.h>
 
 #include "libgimpmath/gimpmath.h"
 
@@ -62,6 +65,8 @@ struct _GimpSpinButtonPrivate
 
 static gboolean   gimp_spin_button_scroll    (GtkWidget      *widget,
                                               GdkEventScroll *event);
+static gboolean   gimp_spin_button_key_press (GtkWidget      *widget,
+                                              GdkEventKey    *event);
 static gboolean   gimp_spin_button_focus_in  (GtkWidget      *widget,
                                               GdkEventFocus  *event);
 static gboolean   gimp_spin_button_focus_out (GtkWidget      *widget,
@@ -90,6 +95,7 @@ gimp_spin_button_class_init (GimpSpinButtonClass *klass)
   GtkSpinButtonClass *spin_button_class = GTK_SPIN_BUTTON_CLASS (klass);
 
   widget_class->scroll_event    = gimp_spin_button_scroll;
+  widget_class->key_press_event = gimp_spin_button_key_press;
   widget_class->focus_in_event  = gimp_spin_button_focus_in;
   widget_class->focus_out_event = gimp_spin_button_focus_out;
 
@@ -152,6 +158,52 @@ gimp_spin_button_scroll (GtkWidget      *widget,
   return GTK_WIDGET_CLASS (parent_class)->scroll_event (widget, event);
 }
 
+static gboolean
+gimp_spin_button_key_press (GtkWidget   *widget,
+                            GdkEventKey *event)
+{
+  switch (event->keyval)
+    {
+      case GDK_KEY_Return:
+      case GDK_KEY_KP_Enter:
+      case GDK_KEY_ISO_Enter:
+      case GDK_KEY_Escape:
+        {
+          GtkEntry      *entry       = GTK_ENTRY (widget);
+          GtkSpinButton *spin_button = GTK_SPIN_BUTTON (widget);
+          gchar         *text;
+          gboolean       changed;
+
+          text = g_strdup (gtk_entry_get_text (entry));
+
+          if (event->keyval == GDK_KEY_Escape)
+            {
+              gtk_spin_button_set_value (
+                spin_button,
+                gtk_spin_button_get_value (spin_button));
+            }
+          else
+            {
+              gtk_spin_button_update (spin_button);
+            }
+
+          changed = strcmp (gtk_entry_get_text (entry), text);
+
+          g_free (text);
+
+          if (changed)
+            {
+              gtk_editable_set_position (GTK_EDITABLE (widget), -1);
+
+              return TRUE;
+            }
+        }
+        break;
+    }
+
+  return GTK_WIDGET_CLASS (parent_class)->key_press_event (widget, event);
+}
+
 static gboolean
 gimp_spin_button_focus_in (GtkWidget     *widget,
                            GdkEventFocus *event)