gtk: Add GtkGstBaseWidget

This is a "pseudo" base class. Basically it's a shared instance
and class structure and a shared set of function between the
two widget. It cannot have it's own type like normal base class
since the one instance will implement GtkGLArea while the other
implements GtkDrawingAreay. To workaround this, the parent instance
and class is a union of both.

https://bugzilla.gnome.org/show_bug.cgi?id=752441

3 files changed, 414 insertions, 0 deletions

diff --git a/ext/gtk/Makefile.am b/ext/gtk/Makefile.am
index 45d0be0d2..58b4e3f96 100644
--- a/ext/gtk/Makefile.am
+++ b/ext/gtk/Makefile.am
@@ -8,6 +8,8 @@ lib_LTLIBRARIES =
 
 # source
 sources = \
+	gtkgstbasewidget.c \
+	gtkgstbasewidget.h \
 	gtkgstwidget.c \
 	gtkgstwidget.h \
 	gstgtksink.c \
diff --git a/ext/gtk/gtkgstbasewidget.c b/ext/gtk/gtkgstbasewidget.c
new file mode 100644
index 000000000..972541ff7
--- /dev/null
+++ b/ext/gtk/gtkgstbasewidget.c
@@ -0,0 +1,318 @@
+/*
+ * GStreamer
+ * Copyright (C) 2015 Matthew Waters <matthew@centricular.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <stdio.h>
+
+#include "gtkgstbasewidget.h"
+
+#define DEFAULT_FORCE_ASPECT_RATIO  TRUE
+#define DEFAULT_PAR_N               0
+#define DEFAULT_PAR_D               1
+#define DEFAULT_IGNORE_ALPHA        TRUE
+
+enum
+{
+  PROP_0,
+  PROP_FORCE_ASPECT_RATIO,
+  PROP_PIXEL_ASPECT_RATIO,
+  PROP_IGNORE_ALPHA,
+};
+
+static void
+gtk_gst_base_widget_get_preferred_width (GtkWidget * widget, gint * min,
+    gint * natural)
+{
+  GtkGstBaseWidget *gst_widget = (GtkGstBaseWidget *) widget;
+  gint video_width = gst_widget->display_width;
+
+  if (!gst_widget->negotiated)
+    video_width = 10;
+
+  if (min)
+    *min = 1;
+  if (natural)
+    *natural = video_width;
+}
+
+static void
+gtk_gst_base_widget_get_preferred_height (GtkWidget * widget, gint * min,
+    gint * natural)
+{
+  GtkGstBaseWidget *gst_widget = (GtkGstBaseWidget *) widget;
+  gint video_height = gst_widget->display_height;
+
+  if (!gst_widget->negotiated)
+    video_height = 10;
+
+  if (min)
+    *min = 1;
+  if (natural)
+    *natural = video_height;
+}
+
+static void
+gtk_gst_base_widget_set_property (GObject * object, guint prop_id,
+    const GValue * value, GParamSpec * pspec)
+{
+  GtkGstBaseWidget *gtk_widget = GTK_GST_BASE_WIDGET (object);
+
+  switch (prop_id) {
+    case PROP_FORCE_ASPECT_RATIO:
+      gtk_widget->force_aspect_ratio = g_value_get_boolean (value);
+      break;
+    case PROP_PIXEL_ASPECT_RATIO:
+      gtk_widget->par_n = gst_value_get_fraction_numerator (value);
+      gtk_widget->par_d = gst_value_get_fraction_denominator (value);
+      break;
+    case PROP_IGNORE_ALPHA:
+      gtk_widget->ignore_alpha = g_value_get_boolean (value);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static void
+gtk_gst_base_widget_get_property (GObject * object, guint prop_id,
+    GValue * value, GParamSpec * pspec)
+{
+  GtkGstBaseWidget *gtk_widget = GTK_GST_BASE_WIDGET (object);
+
+  switch (prop_id) {
+    case PROP_FORCE_ASPECT_RATIO:
+      g_value_set_boolean (value, gtk_widget->force_aspect_ratio);
+      break;
+    case PROP_PIXEL_ASPECT_RATIO:
+      gst_value_set_fraction (value, gtk_widget->par_n, gtk_widget->par_d);
+      break;
+    case PROP_IGNORE_ALPHA:
+      g_value_set_boolean (value, gtk_widget->ignore_alpha);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static gboolean
+_queue_resize (GtkGstBaseWidget * widget)
+{
+  GTK_GST_BASE_WIDGET_LOCK (widget);
+  widget->resize_id = 0;
+
+  GTK_GST_BASE_WIDGET_UNLOCK (widget);
+
+  gtk_widget_queue_resize (GTK_WIDGET (widget));
+
+  return G_SOURCE_REMOVE;
+}
+
+static gboolean
+_calculate_par (GtkGstBaseWidget * widget, GstVideoInfo * info)
+{
+  gboolean ok;
+  gint width, height;
+  gint par_n, par_d;
+  gint display_par_n, display_par_d;
+  guint display_ratio_num, display_ratio_den;
+
+  width = GST_VIDEO_INFO_WIDTH (info);
+  height = GST_VIDEO_INFO_HEIGHT (info);
+
+  par_n = GST_VIDEO_INFO_PAR_N (info);
+  par_d = GST_VIDEO_INFO_PAR_D (info);
+
+  if (!par_n)
+    par_n = 1;
+
+  /* get display's PAR */
+  if (widget->par_n != 0 && widget->par_d != 0) {
+    display_par_n = widget->par_n;
+    display_par_d = widget->par_d;
+  } else {
+    display_par_n = 1;
+    display_par_d = 1;
+  }
+
+  ok = gst_video_calculate_display_ratio (&display_ratio_num,
+      &display_ratio_den, width, height, par_n, par_d, display_par_n,
+      display_par_d);
+
+  if (!ok)
+    return FALSE;
+
+  GST_LOG ("PAR: %u/%u DAR:%u/%u", par_n, par_d, display_par_n, display_par_d);
+
+  if (height % display_ratio_den == 0) {
+    GST_DEBUG ("keeping video height");
+    widget->display_width = (guint)
+        gst_util_uint64_scale_int (height, display_ratio_num,
+        display_ratio_den);
+    widget->display_height = height;
+  } else if (width % display_ratio_num == 0) {
+    GST_DEBUG ("keeping video width");
+    widget->display_width = width;
+    widget->display_height = (guint)
+        gst_util_uint64_scale_int (width, display_ratio_den, display_ratio_num);
+  } else {
+    GST_DEBUG ("approximating while keeping video height");
+    widget->display_width = (guint)
+        gst_util_uint64_scale_int (height, display_ratio_num,
+        display_ratio_den);
+    widget->display_height = height;
+  }
+
+  GST_DEBUG ("scaling to %dx%d", widget->display_width, widget->display_height);
+
+  return TRUE;
+}
+
+static gboolean
+_queue_draw (GtkGstBaseWidget * widget)
+{
+  GTK_GST_BASE_WIDGET_LOCK (widget);
+  widget->draw_id = 0;
+  GTK_GST_BASE_WIDGET_UNLOCK (widget);
+
+  gtk_widget_queue_draw (GTK_WIDGET (widget));
+
+  return G_SOURCE_REMOVE;
+}
+
+void
+gtk_gst_base_widget_class_init (GtkGstBaseWidgetClass * klass)
+{
+  GObjectClass *gobject_klass = (GObjectClass *) klass;
+  GtkWidgetClass *widget_klass = (GtkWidgetClass *) klass;
+
+  gobject_klass->set_property = gtk_gst_base_widget_set_property;
+  gobject_klass->get_property = gtk_gst_base_widget_get_property;
+
+  g_object_class_install_property (gobject_klass, PROP_FORCE_ASPECT_RATIO,
+      g_param_spec_boolean ("force-aspect-ratio",
+          "Force aspect ratio",
+          "When enabled, scaling will respect original aspect ratio",
+          DEFAULT_FORCE_ASPECT_RATIO,
+          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+
+  g_object_class_install_property (gobject_klass, PROP_PIXEL_ASPECT_RATIO,
+      gst_param_spec_fraction ("pixel-aspect-ratio", "Pixel Aspect Ratio",
+          "The pixel aspect ratio of the device", DEFAULT_PAR_N, DEFAULT_PAR_D,
+          G_MAXINT, 1, 1, 1, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+
+  g_object_class_install_property (gobject_klass, PROP_IGNORE_ALPHA,
+      g_param_spec_boolean ("ignore-alpha", "Ignore Alpha",
+          "When enabled, alpha will be ignored and converted to black",
+          DEFAULT_IGNORE_ALPHA, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+
+  widget_klass->get_preferred_width = gtk_gst_base_widget_get_preferred_width;
+  widget_klass->get_preferred_height = gtk_gst_base_widget_get_preferred_height;
+}
+
+void
+gtk_gst_base_widget_init (GtkGstBaseWidget * widget)
+{
+  widget->force_aspect_ratio = DEFAULT_FORCE_ASPECT_RATIO;
+  widget->par_n = DEFAULT_PAR_N;
+  widget->par_d = DEFAULT_PAR_D;
+  widget->ignore_alpha = DEFAULT_IGNORE_ALPHA;
+
+  g_mutex_init (&widget->lock);
+}
+
+void
+gtk_gst_base_widget_finalize (GObject * object)
+{
+  GtkGstBaseWidget *widget = GTK_GST_BASE_WIDGET (object);
+
+  gst_buffer_replace (&widget->buffer, NULL);
+  g_mutex_clear (&widget->lock);
+
+  if (widget->draw_id)
+    g_source_remove (widget->draw_id);
+
+  if (widget->resize_id)
+    g_source_remove (widget->resize_id);
+}
+
+gboolean
+gtk_gst_base_widget_set_caps (GtkGstBaseWidget * widget, GstCaps * caps)
+{
+  GstVideoInfo v_info;
+
+  if (widget->caps && gst_caps_is_equal_fixed (widget->caps, caps))
+    return TRUE;
+
+  if (!gst_video_info_from_caps (&v_info, caps))
+    return FALSE;
+
+  GTK_GST_BASE_WIDGET_LOCK (widget);
+
+  /* FIXME this will cause black frame to be displayed, move this in the
+   * _queue_resize callback passing over the video info */
+
+  if (!_calculate_par (widget, &v_info)) {
+    GTK_GST_BASE_WIDGET_UNLOCK (widget);
+    return FALSE;
+  }
+
+  if (widget->reset)
+    widget->reset (widget);
+
+  gst_buffer_replace (&widget->buffer, NULL);
+  gst_caps_replace (&widget->caps, caps);
+  widget->v_info = v_info;
+  widget->negotiated = TRUE;
+  widget->new_buffer = TRUE;
+
+  if (!widget->resize_id) {
+    widget->resize_id = g_idle_add_full (G_PRIORITY_DEFAULT,
+        (GSourceFunc) _queue_resize, widget, NULL);
+  }
+
+  GTK_GST_BASE_WIDGET_UNLOCK (widget);
+
+  return TRUE;
+}
+
+void
+gtk_gst_base_widget_set_buffer (GtkGstBaseWidget * widget, GstBuffer * buffer)
+{
+  /* As we have no type, this is better then no check */
+  g_return_if_fail (GTK_IS_WIDGET (widget));
+  g_return_if_fail (buffer == NULL || widget->negotiated);
+
+  GTK_GST_BASE_WIDGET_LOCK (widget);
+
+  gst_buffer_replace (&widget->buffer, buffer);
+  widget->new_buffer = TRUE;
+
+  if (!widget->draw_id) {
+    widget->draw_id = g_idle_add_full (G_PRIORITY_DEFAULT,
+        (GSourceFunc) _queue_draw, widget, NULL);
+  }
+
+  GTK_GST_BASE_WIDGET_UNLOCK (widget);
+}
diff --git a/ext/gtk/gtkgstbasewidget.h b/ext/gtk/gtkgstbasewidget.h
new file mode 100644
index 000000000..e4242f192
--- /dev/null
+++ b/ext/gtk/gtkgstbasewidget.h
@@ -0,0 +1,94 @@
+/*
+ * GStreamer
+ * Copyright (C) 2015 Matthew Waters <matthew@centricular.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef __GTK_GST_BASE_WIDGET_H__
+#define __GTK_GST_BASE_WIDGET_H__
+
+#include <gtk/gtk.h>
+#include <gst/gst.h>
+#include <gst/video/video.h>
+
+#define GTK_GST_BASE_WIDGET(w)         ((GtkGstBaseWidget *)(w))
+#define GTK_GST_BASE_WIDGET_CLASS(k)   ((GtkGstBaseWidgetClass *)(k))
+#define GTK_GST_BASE_WIDGET_LOCK(w)    g_mutex_lock(&((GtkGstBaseWidget*)(w))->lock)
+#define GTK_GST_BASE_WIDGET_UNLOCK(w)  g_mutex_unlock(&((GtkGstBaseWidget*)(w))->lock)
+
+G_BEGIN_DECLS
+
+typedef struct _GtkGstBaseWidget GtkGstBaseWidget;
+typedef struct _GtkGstBaseWidgetClass GtkGstBaseWidgetClass;
+
+struct _GtkGstBaseWidget
+{
+  union {
+    GtkDrawingArea drawing_area;
+#if GTK_CHECK_VERSION(3, 15, 0)
+    GtkGLArea gl_area;
+#endif
+  } parent;
+
+  /* properties */
+  gboolean force_aspect_ratio;
+  gint par_n, par_d;
+  gboolean ignore_alpha;
+
+  gint display_width;
+  gint display_height;
+
+  gboolean negotiated;
+  GstBuffer *buffer;
+  GstVideoInfo v_info;
+  gboolean new_buffer;
+
+  /* Poor-man virtual */
+  void (*reset) (GtkGstBaseWidget * widget);
+
+  /*< private >*/
+  GMutex lock;
+  GstCaps *caps;
+
+  /* Pending queued idles callback */
+  guint draw_id;
+  guint resize_id;
+};
+
+struct _GtkGstBaseWidgetClass
+{
+  union {
+    GtkDrawingAreaClass drawing_area_class;
+#if GTK_CHECK_VERSION(3, 15, 0)
+    GtkGLAreaClass gl_area_class;
+#endif
+  } parent_class;
+};
+
+/* For implementer */
+void            gtk_gst_base_widget_class_init           (GtkGstBaseWidgetClass * klass);
+void            gtk_gst_base_widget_init                 (GtkGstBaseWidget * widget);
+
+void            gtk_gst_base_widget_finalize             (GObject * object);
+
+/* API */
+gboolean        gtk_gst_base_widget_set_caps             (GtkGstBaseWidget * widget, GstCaps *caps);
+void            gtk_gst_base_widget_set_buffer           (GtkGstBaseWidget * widget, GstBuffer *buffer);
+
+G_END_DECLS
+
+#endif /* __GTK_GST_BASE_WIDGET_H__ */