Move color scales into separate widget

1 files changed, 297 insertions, 0 deletions

diff --git a/gtk/gtkcolorscale.c b/gtk/gtkcolorscale.c
new file mode 100644
index 0000000000..50c33f8e87
--- /dev/null
+++ b/gtk/gtkcolorscale.c
@@ -0,0 +1,297 @@
+/* GTK - The GIMP Toolkit
+ * Copyright (C) 2012 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include "config.h"
+
+#include "gtkcolorscale.h"
+#include "gtkhsv.h"
+#include "gtkstylecontext.h"
+#include "gtkintl.h"
+
+struct _GtkColorScalePrivate
+{
+  cairo_surface_t *surface;
+  gint width, height;
+  GdkRGBA color;
+  GtkColorScaleType type;
+};
+
+G_DEFINE_TYPE (GtkColorScale, gtk_color_scale, GTK_TYPE_SCALE)
+
+static cairo_pattern_t *
+get_checkered_pattern (void)
+{
+  /* need to respect pixman's stride being a multiple of 4 */
+  static unsigned char data[8] = { 0xFF, 0x00, 0x00, 0x00,
+                                   0x00, 0xFF, 0x00, 0x00 };
+  static cairo_surface_t *checkered = NULL;
+  cairo_pattern_t *pattern;
+
+  if (checkered == NULL)
+    checkered = cairo_image_surface_create_for_data (data,
+                                                     CAIRO_FORMAT_A8,
+                                                     2, 2, 4);
+
+  pattern = cairo_pattern_create_for_surface (checkered);
+  cairo_pattern_set_extend (pattern, CAIRO_EXTEND_REPEAT);
+  cairo_pattern_set_filter (pattern, CAIRO_FILTER_NEAREST);
+
+  return pattern;
+}
+
+static void
+create_h_surface (GtkColorScale *scale)
+{
+  GtkWidget *widget = GTK_WIDGET (scale);
+  cairo_t *cr;
+  cairo_surface_t *surface;
+  gint width, height, stride;
+  cairo_surface_t *tmp;
+  guint red, green, blue;
+  guint32 *data, *p;
+  gdouble h;
+  gdouble r, g, b;
+  gdouble f;
+  gint x, y;
+
+  if (!gtk_widget_get_realized (widget))
+    return;
+
+  width = gtk_widget_get_allocated_width (widget);
+  height = gtk_widget_get_allocated_height (widget);
+
+  if (width != scale->priv->width ||
+      height != scale->priv->height)
+    {
+      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;
+    }
+  else
+    surface = scale->priv->surface;
+
+  if (width == 1 || height == 1)
+    return;
+
+  stride = cairo_format_stride_for_width (CAIRO_FORMAT_RGB24, width);
+
+  data = g_malloc (height * stride);
+
+  f = 1.0 / (height - 1);
+  for (y = 0; y < height; y++)
+    {
+      h = CLAMP (y * f, 0.0, 1.0);
+      p = data + y * (stride / 4);
+      for (x = 0; x < width; x++)
+        {
+          gtk_hsv_to_rgb (h, 1, 1, &r, &g, &b);
+          red = CLAMP (r * 255, 0, 255);
+          green = CLAMP (g * 255, 0, 255);
+          blue = CLAMP (b * 255, 0, 255);
+          p[x] = (red << 16) | (green << 8) | blue;
+        }
+    }
+
+  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);
+}
+
+static void
+create_a_surface (GtkColorScale *scale)
+{
+  GtkWidget *widget = GTK_WIDGET (scale);
+  cairo_t *cr;
+  cairo_surface_t *surface;
+  cairo_pattern_t *pattern;
+  cairo_matrix_t matrix;
+  GdkRGBA *color;
+  gint width, height;
+
+  if (!gtk_widget_get_realized (widget))
+    return;
+
+  width = gtk_widget_get_allocated_width (widget);
+  height = gtk_widget_get_allocated_height (widget);
+
+  if (!scale->priv->surface ||
+      width != scale->priv->width ||
+      height != scale->priv->height)
+    {
+      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;
+    }
+  else
+    return;
+
+  if (width == 1 || height == 1)
+    return;
+
+  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);
+
+  pattern = get_checkered_pattern ();
+  cairo_matrix_init_scale (&matrix, 0.125, 0.125);
+  cairo_pattern_set_matrix (pattern, &matrix);
+  cairo_mask (cr, pattern);
+  cairo_pattern_destroy (pattern);
+
+  color = &scale->priv->color;
+
+  pattern = cairo_pattern_create_linear (0, 0, width, 0);
+  cairo_pattern_add_color_stop_rgba (pattern, 0, color->red, color->green, color->blue, 0);
+  cairo_pattern_add_color_stop_rgba (pattern, width, color->red, color->green, color->blue, 1);
+  cairo_set_source (cr, pattern);
+  cairo_paint (cr);
+  cairo_pattern_destroy (pattern);
+
+  cairo_destroy (cr);
+}
+
+static void
+create_surface (GtkColorScale *scale)
+{
+  switch (scale->priv->type)
+    {
+    case GTK_COLOR_SCALE_HUE:
+      create_h_surface (scale);
+      break;
+    case GTK_COLOR_SCALE_ALPHA:
+      create_a_surface (scale);
+      break;
+    }
+}
+
+static gboolean
+scale_draw (GtkWidget *widget,
+            cairo_t   *cr)
+{
+  GtkColorScale *scale = GTK_COLOR_SCALE (widget);
+  gint width, height;
+
+  width = gtk_widget_get_allocated_width (widget);
+  height = gtk_widget_get_allocated_height (widget);
+
+  create_surface (scale);
+
+  cairo_save (cr);
+
+  cairo_rectangle (cr, 1, 1, width - 2, height - 2);
+  cairo_clip (cr);
+  cairo_set_source_surface (cr, scale->priv->surface, 0, 0);
+  cairo_paint (cr);
+
+  cairo_restore (cr);
+
+  GTK_WIDGET_CLASS (gtk_color_scale_parent_class)->draw (widget, cr);
+
+  return FALSE;
+}
+
+static void
+gtk_color_scale_init (GtkColorScale *scale)
+{
+  scale->priv = G_TYPE_INSTANCE_GET_PRIVATE (scale,
+                                             GTK_TYPE_COLOR_SCALE,
+                                             GtkColorScalePrivate);
+
+  scale->priv->type = GTK_COLOR_SCALE_HUE;
+}
+
+static void
+scale_finalize (GObject *object)
+{
+  GtkColorScale *scale = GTK_COLOR_SCALE (object);
+
+  if (scale->priv->surface)
+    cairo_surface_destroy (scale->priv->surface);
+
+  G_OBJECT_CLASS (gtk_color_scale_parent_class)->finalize (object);
+}
+
+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;
+
+  widget_class->draw = scale_draw;
+
+  g_type_class_add_private (class, sizeof (GtkColorScalePrivate));
+}
+
+void
+gtk_color_scale_set_color (GtkColorScale *scale,
+                           const GdkRGBA *color)
+{
+  scale->priv->color.red = color->red;
+  scale->priv->color.green = color->green;
+  scale->priv->color.blue = color->blue;
+  scale->priv->color.alpha = color->alpha;
+  if (scale->priv->surface)
+    {
+      cairo_surface_destroy (scale->priv->surface);
+      scale->priv->surface = NULL;
+    }
+  create_surface (scale);
+  gtk_widget_queue_draw (GTK_WIDGET (scale));
+}
+
+void
+gtk_color_scale_set_type (GtkColorScale     *scale,
+                          GtkColorScaleType  type)
+{
+  scale->priv->type = type;
+  cairo_surface_destroy (scale->priv->surface);
+  scale->priv->surface = NULL;
+  create_surface (scale);
+  gtk_widget_queue_draw (GTK_WIDGET (scale));
+}
+
+GtkWidget *
+gtk_color_scale_new (void)
+{
+  return (GtkWidget *) g_object_new (GTK_TYPE_COLOR_SCALE,
+                                     "adjustment", gtk_adjustment_new (0, 0, 1, 0.01, 0.1, 0),
+                                     "draw-value", FALSE,
+                                     NULL);
+}