[gimp] app: add a guide line canvas item class

[Michael Natterer <mitch src gnome org>]

commit 8dbab53faea5f4de03b6637b2cb4d6d77a142767
Author: Michael Natterer <mitch gimp org>
Date:   Thu Sep 23 14:51:45 2010 +0200

    app: add a guide line canvas item class

 app/display/Makefile.am       |    2 +
 app/display/gimpcanvasguide.c |  236 +++++++++++++++++++++++++++++++++++++++++
 app/display/gimpcanvasguide.h |   56 ++++++++++
 3 files changed, 294 insertions(+), 0 deletions(-)
---
diff --git a/app/display/Makefile.am b/app/display/Makefile.am
index 6135453..473eba3 100644
--- a/app/display/Makefile.am
+++ b/app/display/Makefile.am
@@ -19,6 +19,8 @@ libappdisplay_a_sources = \
 	display-types.h				\
 	gimpcanvas.c				\
 	gimpcanvas.h				\
+	gimpcanvasguide.c			\
+	gimpcanvasguide.h			\
 	gimpcanvashandle.c			\
 	gimpcanvashandle.h			\
 	gimpcanvasitem.c			\
diff --git a/app/display/gimpcanvasguide.c b/app/display/gimpcanvasguide.c
new file mode 100644
index 0000000..825a9eb
--- /dev/null
+++ b/app/display/gimpcanvasguide.c
@@ -0,0 +1,236 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvasguide.c
+ * Copyright (C) 2010 Michael Natterer <mitch gimp org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "gimpcanvasguide.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-transform.h"
+
+
+enum
+{
+  PROP_0,
+  PROP_ORIENTATION,
+  PROP_POSITION
+};
+
+
+typedef struct _GimpCanvasGuidePrivate GimpCanvasGuidePrivate;
+
+struct _GimpCanvasGuidePrivate
+{
+  GimpOrientationType orientation;
+  gint                position;
+};
+
+#define GET_PRIVATE(guide) \
+        G_TYPE_INSTANCE_GET_PRIVATE (guide, \
+                                     GIMP_TYPE_CANVAS_GUIDE, \
+                                     GimpCanvasGuidePrivate)
+
+
+/*  local function prototypes  */
+
+static void        gimp_canvas_guide_set_property (GObject          *object,
+                                                  guint             property_id,
+                                                  const GValue     *value,
+                                                  GParamSpec       *pspec);
+static void        gimp_canvas_guide_get_property (GObject          *object,
+                                                  guint             property_id,
+                                                  GValue           *value,
+                                                  GParamSpec       *pspec);
+static void        gimp_canvas_guide_draw         (GimpCanvasItem   *item,
+                                                  GimpDisplayShell *shell,
+                                                  cairo_t          *cr);
+static GdkRegion * gimp_canvas_guide_get_extents  (GimpCanvasItem   *item,
+                                                  GimpDisplayShell *shell);
+
+
+G_DEFINE_TYPE (GimpCanvasGuide, gimp_canvas_guide, GIMP_TYPE_CANVAS_ITEM)
+
+#define parent_class gimp_canvas_guide_parent_class
+
+
+static void
+gimp_canvas_guide_class_init (GimpCanvasGuideClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpCanvasItemClass *item_class   = GIMP_CANVAS_ITEM_CLASS (klass);
+
+  object_class->set_property = gimp_canvas_guide_set_property;
+  object_class->get_property = gimp_canvas_guide_get_property;
+
+  item_class->draw           = gimp_canvas_guide_draw;
+  item_class->get_extents    = gimp_canvas_guide_get_extents;
+
+  g_object_class_install_property (object_class, PROP_ORIENTATION,
+                                   g_param_spec_enum ("orientation", NULL, NULL,
+                                                      GIMP_TYPE_ORIENTATION_TYPE,
+                                                      GIMP_ORIENTATION_HORIZONTAL,
+                                                      GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_POSITION,
+                                   g_param_spec_int ("position", NULL, NULL,
+                                                     -GIMP_MAX_IMAGE_SIZE,
+                                                     GIMP_MAX_IMAGE_SIZE, 0,
+                                                     GIMP_PARAM_READWRITE));
+
+  g_type_class_add_private (klass, sizeof (GimpCanvasGuidePrivate));
+}
+
+static void
+gimp_canvas_guide_init (GimpCanvasGuide *guide)
+{
+}
+
+static void
+gimp_canvas_guide_set_property (GObject      *object,
+                                guint         property_id,
+                                const GValue *value,
+                                GParamSpec   *pspec)
+{
+  GimpCanvasGuidePrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_ORIENTATION:
+      private->orientation = g_value_get_enum (value);
+      break;
+    case PROP_POSITION:
+      private->position = g_value_get_int (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_guide_get_property (GObject    *object,
+                                guint       property_id,
+                                GValue     *value,
+                                GParamSpec *pspec)
+{
+  GimpCanvasGuidePrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_ORIENTATION:
+      g_value_set_enum (value, private->orientation);
+      break;
+    case PROP_POSITION:
+      g_value_set_int (value, private->position);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_guide_transform (GimpCanvasItem   *item,
+                             GimpDisplayShell *shell,
+                             gdouble          *x1,
+                             gdouble          *y1,
+                             gdouble          *x2,
+                             gdouble          *y2)
+{
+  GimpCanvasGuidePrivate *private = GET_PRIVATE (item);
+  GtkAllocation           allocation;
+  gint                    x, y;
+
+  gtk_widget_get_allocation (shell->canvas, &allocation);
+
+  *x1 = 0;
+  *y1 = 0;
+  *x2 = allocation.width;
+  *y2 = allocation.height;
+
+  switch (private->orientation)
+    {
+    case GIMP_ORIENTATION_HORIZONTAL:
+      gimp_display_shell_transform_xy (shell, 0, private->position, &x, &y);
+      *y1 = *y2 = y + 0.5;
+      break;
+
+    case GIMP_ORIENTATION_VERTICAL:
+      gimp_display_shell_transform_xy (shell, private->position, 0, &x, &y);
+      *x1 = *x2 = x + 0.5;
+      break;
+
+    case GIMP_ORIENTATION_UNKNOWN:
+      return;
+    }
+}
+
+static void
+gimp_canvas_guide_draw (GimpCanvasItem   *item,
+                       GimpDisplayShell *shell,
+                       cairo_t          *cr)
+{
+  gdouble x1, y1;
+  gdouble x2, y2;
+
+  gimp_canvas_guide_transform (item, shell, &x1, &y1, &x2, &y2);
+
+  cairo_move_to (cr, x1, y1);
+  cairo_line_to (cr, x2, y2);
+
+  _gimp_canvas_item_stroke (item, shell, cr);
+}
+
+static GdkRegion *
+gimp_canvas_guide_get_extents (GimpCanvasItem   *item,
+                               GimpDisplayShell *shell)
+{
+  GdkRectangle rectangle;
+  gdouble      x1, y1;
+  gdouble      x2, y2;
+
+  gimp_canvas_guide_transform (item, shell, &x1, &y1, &x2, &y2);
+
+  rectangle.x      = MIN (x1, x2) - 1.5;
+  rectangle.y      = MIN (y1, y2) - 1.5;
+  rectangle.width  = ABS (x2 - x1) + 3.0;
+  rectangle.height = ABS (y2 - y1) + 3.0;
+
+  return gdk_region_rectangle (&rectangle);
+}
+
+GimpCanvasItem *
+gimp_canvas_guide_new (GimpOrientationType  orientation,
+                       gint                 position)
+{
+  return g_object_new (GIMP_TYPE_CANVAS_GUIDE,
+                       "orientation", orientation,
+                       "position",    position,
+                       NULL);
+}
diff --git a/app/display/gimpcanvasguide.h b/app/display/gimpcanvasguide.h
new file mode 100644
index 0000000..bd4eadb
--- /dev/null
+++ b/app/display/gimpcanvasguide.h
@@ -0,0 +1,56 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvasguide.h
+ * Copyright (C) 2010 Michael Natterer <mitch gimp org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_GUIDE_H__
+#define __GIMP_CANVAS_GUIDE_H__
+
+
+#include "gimpcanvasitem.h"
+
+
+#define GIMP_TYPE_CANVAS_GUIDE            (gimp_canvas_guide_get_type ())
+#define GIMP_CANVAS_GUIDE(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CANVAS_GUIDE, GimpCanvasGuide))
+#define GIMP_CANVAS_GUIDE_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CANVAS_GUIDE, GimpCanvasGuideClass))
+#define GIMP_IS_CANVAS_GUIDE(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CANVAS_GUIDE))
+#define GIMP_IS_CANVAS_GUIDE_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CANVAS_GUIDE))
+#define GIMP_CANVAS_GUIDE_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS_GUIDE, GimpCanvasGuideClass))
+
+
+typedef struct _GimpCanvasGuide      GimpCanvasGuide;
+typedef struct _GimpCanvasGuideClass GimpCanvasGuideClass;
+
+struct _GimpCanvasGuide
+{
+  GimpCanvasItem  parent_instance;
+};
+
+struct _GimpCanvasGuideClass
+{
+  GimpCanvasItemClass  parent_class;
+};
+
+
+GType            gimp_canvas_guide_get_type (void) G_GNUC_CONST;
+
+GimpCanvasItem * gimp_canvas_guide_new      (GimpOrientationType  orientation,
+                                             gint                 position);
+
+
+#endif /* __GIMP_CANVAS_GUIDE_H__ */