[gnome-builder/wip/gtk4-port] libide/gui: add show/hide with fade API

[Christian Hergert <chergert src gnome org>]

commit 69e8be9f3a20c7a3b5861955ec58b336a86d95ce
Author: Christian Hergert <chergert redhat com>
Date:   Tue Mar 29 11:50:47 2022 -0700

    libide/gui: add show/hide with fade API
    
    This is just a straitforward port of what we were using previously.

 src/libide/gtk/ide-gtk.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++++
 src/libide/gtk/ide-gtk.h |  4 +++
 2 files changed, 85 insertions(+)
---
diff --git a/src/libide/gtk/ide-gtk.c b/src/libide/gtk/ide-gtk.c
index 423441d55..34d68c73d 100644
--- a/src/libide/gtk/ide-gtk.c
+++ b/src/libide/gtk/ide-gtk.c
@@ -24,6 +24,7 @@
 
 #include <libide-threading.h>
 
+#include "ide-animation.h"
 #include "ide-gtk.h"
 
 void
@@ -146,3 +147,83 @@ ide_gtk_progress_bar_start_pulsing (GtkProgressBar *progress)
   g_object_set_data (G_OBJECT (progress), "PULSE_ID", GUINT_TO_POINTER (tick_id));
   ide_gtk_progress_bar_tick_cb (progress);
 }
+
+static void
+show_callback (gpointer data)
+{
+  g_object_set_data (data, "IDE_FADE_ANIMATION", NULL);
+  g_object_unref (data);
+}
+
+static void
+hide_callback (gpointer data)
+{
+  GtkWidget *widget = data;
+
+  g_object_set_data (data, "IDE_FADE_ANIMATION", NULL);
+  gtk_widget_hide (widget);
+  gtk_widget_set_opacity (widget, 1.0);
+  g_object_unref (widget);
+}
+
+void
+ide_gtk_widget_show_with_fade (GtkWidget *widget)
+{
+  GdkFrameClock *frame_clock;
+  IdeAnimation *anim;
+
+  g_return_if_fail (GTK_IS_WIDGET (widget));
+
+  if (!gtk_widget_get_visible (widget))
+    {
+      anim = g_object_get_data (G_OBJECT (widget), "IDE_FADE_ANIMATION");
+      if (anim != NULL)
+        ide_animation_stop (anim);
+
+      frame_clock = gtk_widget_get_frame_clock (widget);
+      gtk_widget_set_opacity (widget, 0.0);
+      gtk_widget_show (widget);
+      anim = ide_object_animate_full (widget,
+                                      IDE_ANIMATION_LINEAR,
+                                      500,
+                                      frame_clock,
+                                      show_callback,
+                                      g_object_ref (widget),
+                                      "opacity", 1.0,
+                                      NULL);
+      g_object_set_data_full (G_OBJECT (widget),
+                              "IDE_FADE_ANIMATION",
+                              g_object_ref (anim),
+                              g_object_unref);
+    }
+}
+
+void
+ide_gtk_widget_hide_with_fade (GtkWidget *widget)
+{
+  GdkFrameClock *frame_clock;
+  IdeAnimation *anim;
+
+  g_return_if_fail (GTK_IS_WIDGET (widget));
+
+  if (gtk_widget_get_visible (widget))
+    {
+      anim = g_object_get_data (G_OBJECT (widget), "IDE_FADE_ANIMATION");
+      if (anim != NULL)
+        ide_animation_stop (anim);
+
+      frame_clock = gtk_widget_get_frame_clock (widget);
+      anim = ide_object_animate_full (widget,
+                                      IDE_ANIMATION_LINEAR,
+                                      1000,
+                                      frame_clock,
+                                      hide_callback,
+                                      g_object_ref (widget),
+                                      "opacity", 0.0,
+                                      NULL);
+      g_object_set_data_full (G_OBJECT (widget),
+                              "IDE_FADE_ANIMATION",
+                              g_object_ref (anim),
+                              g_object_unref);
+    }
+}
diff --git a/src/libide/gtk/ide-gtk.h b/src/libide/gtk/ide-gtk.h
index 5e8d6557e..2632d9845 100644
--- a/src/libide/gtk/ide-gtk.h
+++ b/src/libide/gtk/ide-gtk.h
@@ -41,5 +41,9 @@ IDE_AVAILABLE_IN_ALL
 void      ide_gtk_progress_bar_start_pulsing (GtkProgressBar  *progress);
 IDE_AVAILABLE_IN_ALL
 void      ide_gtk_progress_bar_stop_pulsing  (GtkProgressBar  *progress);
+IDE_AVAILABLE_IN_ALL
+void      ide_gtk_widget_show_with_fade      (GtkWidget       *widget);
+IDE_AVAILABLE_IN_ALL
+void      ide_gtk_widget_hide_with_fade      (GtkWidget       *widget);
 
 G_END_DECLS