[gtk+] colorscale: Draw a trough

[Benjamin Otte <otte src gnome org>]

commit fc7335bdb4c1bed38b7287354d348af949c20ace
Author: Benjamin Otte <otte redhat com>
Date:   Wed Mar 9 17:27:01 2016 +0100

    colorscale: Draw a trough
    
    Make sure the color info is actually drawn inside the trough.

 gtk/gtkcolorscale.c        |  157 +++++--------------------------------------
 gtk/gtkcolorscaleprivate.h |    7 ++
 gtk/gtkrange.c             |   12 ++--
 gtk/ui/gtkcoloreditor.ui   |    2 +
 4 files changed, 35 insertions(+), 143 deletions(-)
---
diff --git a/gtk/gtkcolorscale.c b/gtk/gtkcolorscale.c
index fd03029..be1123d 100644
--- a/gtk/gtkcolorscale.c
+++ b/gtk/gtkcolorscale.c
@@ -34,8 +34,6 @@
 
 struct _GtkColorScalePrivate
 {
-  cairo_surface_t *surface;
-  gint width, height;
   GdkRGBA color;
   GtkColorScaleType type;
 
@@ -55,97 +53,35 @@ static void hold_action (GtkGestureLongPress *gesture,
 
 G_DEFINE_TYPE_WITH_PRIVATE (GtkColorScale, gtk_color_scale, GTK_TYPE_SCALE)
 
-static void
-gtk_color_scale_get_trough_size (GtkColorScale *scale,
-                                 gint *x_offset_out,
-                                 gint *y_offset_out,
-                                 gint *width_out,
-                                 gint *height_out)
-{
-  GtkWidget *widget = GTK_WIDGET (scale);
-  GtkCssGadget *slider_gadget;
-  gint width, height;
-  gint x_offset, y_offset;
-  gint slider_width, slider_height;
-
-  slider_gadget = gtk_range_get_slider_gadget (GTK_RANGE (scale));
-  gtk_css_gadget_get_preferred_size (slider_gadget,
-                                     GTK_ORIENTATION_HORIZONTAL, -1,
-                                     &slider_width, NULL,
-                                     NULL, NULL);
-  gtk_css_gadget_get_preferred_size (slider_gadget,
-                                     GTK_ORIENTATION_VERTICAL, -1,
-                                     &slider_height, NULL,
-                                     NULL, NULL);
-
-  width = gtk_widget_get_allocated_width (widget);
-  height = gtk_widget_get_allocated_height (widget);
-
-  x_offset = 0;
-  y_offset = 0;
-
-  /* if the slider has a vertical shape, draw the trough asymmetric */
-  if (slider_width > slider_height)
-    {
-      if (gtk_orientable_get_orientation (GTK_ORIENTABLE (widget)) == GTK_ORIENTATION_VERTICAL)
-        {
-          if (gtk_widget_get_direction (widget) == GTK_TEXT_DIR_LTR)
-            x_offset += (gint) floor (slider_width / 2.0);
-
-          width = (gint) floor (slider_width / 2.0);
-        }
-      else
-        {
-          height = (gint) floor (slider_width / 2.0);
-        }
-    }
-
-  if (width_out)
-    *width_out = width;
-  if (height_out)
-    *height_out = height;
-  if (x_offset_out)
-    *x_offset_out = x_offset;
-  if (y_offset_out)
-    *y_offset_out = y_offset;
-}
-
-static void
-create_surface (GtkColorScale *scale)
+void
+gtk_color_scale_draw_trough (GtkColorScale  *scale,
+                             cairo_t        *cr,
+                             int             x,
+                             int             y,
+                             int             width,
+                             int             height)
 {
-  GtkWidget *widget = GTK_WIDGET (scale);
-  cairo_surface_t *surface;
-  gint width, height;
+  GtkWidget *widget;
 
-  if (!gtk_widget_get_realized (widget))
+  if (width <= 1 || height <= 1)
     return;
 
-  gtk_color_scale_get_trough_size (scale,
-                                   NULL, NULL,
-                                   &width, &height);
+  cairo_save (cr);
+  cairo_translate (cr, x, y);
+
+  widget = GTK_WIDGET (scale);
+  cairo_rectangle (cr, 0, 0, width, height);
+  cairo_clip (cr);
 
-  if (!scale->priv->surface ||
-      width != scale->priv->width ||
-      height != scale->priv->height)
+  if (gtk_orientable_get_orientation (GTK_ORIENTABLE (widget)) == GTK_ORIENTATION_HORIZONTAL &&
+      gtk_widget_get_direction (widget) == GTK_TEXT_DIR_RTL)
     {
-      surface = gdk_window_create_similar_surface (gtk_widget_get_window (widget),
-                                                   CAIRO_CONTENT_COLOR,
-                                                   width, height);
-      if (scale->priv->surface)
-        cairo_surface_destroy (scale->priv->surface);
-      scale->priv->surface = surface;
-      scale->priv->width = width;
-      scale->priv->height= height;
+      cairo_translate (cr, width, 0);
+      cairo_scale (cr, -1, 1);
     }
-  else
-    surface = scale->priv->surface;
-
-  if (width == 1 || height == 1)
-    return;
 
   if (scale->priv->type == GTK_COLOR_SCALE_HUE)
     {
-      cairo_t *cr;
       gint stride;
       cairo_surface_t *tmp;
       guint red, green, blue;
@@ -176,24 +112,19 @@ create_surface (GtkColorScale *scale)
 
       tmp = cairo_image_surface_create_for_data ((guchar *)data, CAIRO_FORMAT_RGB24,
                                                  width, height, stride);
-      cr = cairo_create (surface);
 
       cairo_set_source_surface (cr, tmp, 0, 0);
       cairo_paint (cr);
 
-      cairo_destroy (cr);
       cairo_surface_destroy (tmp);
       g_free (data);
     }
   else if (scale->priv->type == GTK_COLOR_SCALE_ALPHA)
     {
-      cairo_t *cr;
       cairo_pattern_t *pattern;
       cairo_matrix_t matrix;
       GdkRGBA *color;
 
-      cr = cairo_create (surface);
-
       cairo_set_source_rgb (cr, 0.33, 0.33, 0.33);
       cairo_paint (cr);
       cairo_set_source_rgb (cr, 0.66, 0.66, 0.66);
@@ -212,51 +143,9 @@ create_surface (GtkColorScale *scale)
       cairo_set_source (cr, pattern);
       cairo_paint (cr);
       cairo_pattern_destroy (pattern);
-
-      cairo_destroy (cr);
     }
-}
-
-static gboolean
-scale_draw (GtkWidget *widget,
-            cairo_t   *cr)
-{
-  GtkColorScale *scale = GTK_COLOR_SCALE (widget);
-  gint width, height, x_offset, y_offset;
-  cairo_pattern_t *pattern;
-  GtkStyleContext *context;
-
-  create_surface (scale);
-  gtk_color_scale_get_trough_size (scale,
-                                   &x_offset, &y_offset,
-                                   &width, &height);
-
-  cairo_save (cr);
-  cairo_translate (cr, x_offset, y_offset);
-
-  context = gtk_widget_get_style_context (widget);
-  gtk_render_content_path (context, cr, 0, 0, width, height);
-
-  pattern = cairo_pattern_create_for_surface (scale->priv->surface);
-  if (gtk_orientable_get_orientation (GTK_ORIENTABLE (widget)) == GTK_ORIENTATION_HORIZONTAL &&
-      gtk_widget_get_direction (widget) == GTK_TEXT_DIR_RTL)
-    {
-      cairo_matrix_t matrix;
-
-      cairo_matrix_init_scale (&matrix, -1, 1);
-      cairo_matrix_translate (&matrix, -width, 0);
-      cairo_pattern_set_matrix (pattern, &matrix);
-    }
-  cairo_set_source (cr, pattern);
-  cairo_fill (cr);
-
-  cairo_pattern_destroy (pattern);
 
   cairo_restore (cr);
-
-  GTK_WIDGET_CLASS (gtk_color_scale_parent_class)->draw (widget, cr);
-
-  return FALSE;
 }
 
 static void
@@ -283,9 +172,6 @@ scale_finalize (GObject *object)
 {
   GtkColorScale *scale = GTK_COLOR_SCALE (object);
 
-  if (scale->priv->surface)
-    cairo_surface_destroy (scale->priv->surface);
-
   g_clear_object (&scale->priv->long_press_gesture);
 
   G_OBJECT_CLASS (gtk_color_scale_parent_class)->finalize (object);
@@ -363,14 +249,11 @@ static void
 gtk_color_scale_class_init (GtkColorScaleClass *class)
 {
   GObjectClass *object_class = G_OBJECT_CLASS (class);
-  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (class);
 
   object_class->finalize = scale_finalize;
   object_class->get_property = scale_get_property;
   object_class->set_property = scale_set_property;
 
-  widget_class->draw = scale_draw;
-
   g_object_class_install_property (object_class, PROP_SCALE_TYPE,
       g_param_spec_int ("scale-type", P_("Scale type"), P_("Scale type"),
                         0, 1, 0,
@@ -382,8 +265,6 @@ gtk_color_scale_set_rgba (GtkColorScale *scale,
                           const GdkRGBA *color)
 {
   scale->priv->color = *color;
-  scale->priv->width = -1; /* force surface refresh */
-  create_surface (scale);
   gtk_widget_queue_draw (GTK_WIDGET (scale));
 }
 
diff --git a/gtk/gtkcolorscaleprivate.h b/gtk/gtkcolorscaleprivate.h
index 9ce776b..15b3324 100644
--- a/gtk/gtkcolorscaleprivate.h
+++ b/gtk/gtkcolorscaleprivate.h
@@ -64,6 +64,13 @@ GtkWidget * gtk_color_scale_new      (GtkAdjustment     *adjustment,
 void        gtk_color_scale_set_rgba (GtkColorScale     *scale,
                                       const GdkRGBA     *color);
 
+void        gtk_color_scale_draw_trough (GtkColorScale  *scale,
+                                         cairo_t        *cr,
+                                         int             x,
+                                         int             y,
+                                         int             width,
+                                         int             height);
+
 G_END_DECLS
 
 #endif /* __GTK_COLOR_SCALE_H__ */
diff --git a/gtk/gtkrange.c b/gtk/gtkrange.c
index 50357c2..9b78108 100644
--- a/gtk/gtkrange.c
+++ b/gtk/gtkrange.c
@@ -2355,6 +2355,12 @@ gtk_range_render_trough (GtkCssGadget *gadget,
   GtkRange *range = GTK_RANGE (widget);
   GtkRangePrivate *priv = range->priv;
 
+  /* HACK: GtkColorScale wants to draw its own trough
+   * so we let it...
+   */
+  if (GTK_IS_COLOR_SCALE (widget))
+    gtk_color_scale_draw_trough (GTK_COLOR_SCALE (widget), cr, x, y, width, height);
+
   if (priv->show_fill_level &&
       gtk_adjustment_get_upper (priv->adjustment) - gtk_adjustment_get_page_size (priv->adjustment) -
       gtk_adjustment_get_lower (priv->adjustment) != 0)
@@ -2379,11 +2385,7 @@ gtk_range_render (GtkCssGadget *gadget,
   GtkRange *range = GTK_RANGE (widget);
   GtkRangePrivate *priv = range->priv;
 
-  /* HACK: we can't render the contents box directly because
-   * GtkColorScale wants to omit the trough but still draw the slider...
-   */
-  if (!GTK_IS_COLOR_SCALE (widget))
-    gtk_css_gadget_draw (priv->contents_gadget, cr);
+  gtk_css_gadget_draw (priv->contents_gadget, cr);
 
   /* Draw the slider last, so that e.g. the focus ring stays below it */
   gtk_css_gadget_draw (priv->slider_gadget, cr);
diff --git a/gtk/ui/gtkcoloreditor.ui b/gtk/ui/gtkcoloreditor.ui
index 1c3e971..664b1b5 100644
--- a/gtk/ui/gtkcoloreditor.ui
+++ b/gtk/ui/gtkcoloreditor.ui
@@ -80,6 +80,7 @@
                 <property name="orientation">vertical</property>
                 <property name="adjustment">h_adj</property>
                 <property name="draw_value">False</property>
+                <property name="has_origin">False</property>
                 <signal name="popup-menu" handler="popup_edit" swapped="no"/>
               </object>
               <packing>
@@ -94,6 +95,7 @@
                 <property name="adjustment">a_adj</property>
                 <property name="draw_value">False</property>
                 <property name="scale_type">1</property>
+                <property name="has_origin">False</property>
                 <style>
                   <class name="scale-has-marks-above"/>
                 </style>