From efc3ad6f5ccfb0f63eaa197a154cbf724e3a2662 Mon Sep 17 00:00:00 2001
From: Přemysl Janouch
Date: Sun, 19 Sep 2010 09:10:16 +0200
Subject: Implemented a skeleton of LdCanvas.
It now paints itself white and draws a simple grid.
Also an LdDocument can be assigned to it.
---
src/ld-canvas.c | 160 ++++++++++++++++++++++++++++++++++++++++++++++++++-
src/ld-canvas.h | 10 ++++
src/ld-window-main.c | 2 +-
3 files changed, 168 insertions(+), 4 deletions(-)
diff --git a/src/ld-canvas.c b/src/ld-canvas.c
index 06b12d2..32ec444 100644
--- a/src/ld-canvas.c
+++ b/src/ld-canvas.c
@@ -13,10 +13,9 @@
#include "config.h"
#include "ld-marshal.h"
-#include "ld-canvas.h"
#include "ld-document.h"
+#include "ld-canvas.h"
-/* http://www.gnomejournal.org/article/34/writing-a-widget-using-cairo-and-gtk28 */
/**
* SECTION:ld-canvas
@@ -37,19 +36,56 @@ struct _LdCanvasPrivate
G_DEFINE_TYPE (LdCanvas, ld_canvas, GTK_TYPE_DRAWING_AREA);
+enum
+{
+ PROP_0,
+ PROP_DOCUMENT
+};
+
+static void
+ld_canvas_get_property (GObject *object, guint property_id,
+ GValue *value, GParamSpec *pspec);
+
+static void
+ld_canvas_set_property (GObject *object, guint property_id,
+ const GValue *value, GParamSpec *pspec);
+
static void
ld_canvas_finalize (GObject *gobject);
+static gboolean
+on_expose_event (GtkWidget *widget, GdkEventExpose *event, gpointer user_data);
+
+static void
+draw_grid (GtkWidget *widget, cairo_t *cr);
+
+static void
+canvas_paint (GtkWidget *widget, cairo_t *cr);
+
+
static void
ld_canvas_class_init (LdCanvasClass *klass)
{
GObjectClass *object_class;
GtkWidgetClass *widget_class;
+ GParamSpec *pspec;
object_class = G_OBJECT_CLASS (klass);
+ object_class->get_property = ld_canvas_get_property;
+ object_class->set_property = ld_canvas_set_property;
object_class->finalize = ld_canvas_finalize;
+/**
+ * LdCanvas:document:
+ *
+ * The underlying #LdDocument object of this canvas.
+ */
+ pspec = g_param_spec_object ("document", "Document",
+ "The underlying document object of this canvas.",
+ LD_TYPE_DOCUMENT, G_PARAM_READWRITE);
+ g_object_class_install_property (object_class, PROP_DOCUMENT, pspec);
+
widget_class = GTK_WIDGET_CLASS (klass);
/* TODO: Scrolling support; make the comment bellow a gtk-doc comment then. */
@@ -63,7 +99,7 @@ ld_canvas_class_init (LdCanvasClass *klass)
widget_class->set_scroll_adjustments_signal = g_signal_new
("set-scroll-adjustments", G_TYPE_FROM_CLASS (widget_class),
G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
- 0, // G_STRUCT_OFFSET (LdCanvasClass, ...)
+ G_STRUCT_OFFSET (LdCanvasClass, set_scroll_adjustments),
NULL, NULL,
g_cclosure_user_marshal_VOID__OBJECT_OBJECT,
G_TYPE_NONE, 2, GTK_TYPE_ADJUSTMENT, GTK_TYPE_ADJUSTMENT);
@@ -76,6 +112,8 @@ ld_canvas_init (LdCanvas *self)
{
self->priv = G_TYPE_INSTANCE_GET_PRIVATE
(self, LD_TYPE_CANVAS, LdCanvasPrivate);
+
+ g_signal_connect (self, "expose-event", G_CALLBACK (on_expose_event), NULL);
}
static void
@@ -89,6 +127,40 @@ ld_canvas_finalize (GObject *gobject)
G_OBJECT_CLASS (ld_canvas_parent_class)->finalize (gobject);
}
+static void
+ld_canvas_get_property (GObject *object, guint property_id,
+ GValue *value, GParamSpec *pspec)
+{
+ LdCanvas *self;
+
+ self = LD_CANVAS (object);
+ switch (property_id)
+ {
+ case PROP_DOCUMENT:
+ g_value_set_object (value, ld_canvas_get_document (self));
+ break;
+ default:
+ G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+ }
+}
+
+static void
+ld_canvas_set_property (GObject *object, guint property_id,
+ const GValue *value, GParamSpec *pspec)
+{
+ LdCanvas *self;
+
+ self = LD_CANVAS (object);
+ switch (property_id)
+ {
+ case PROP_DOCUMENT:
+ ld_canvas_set_document (self, LD_DOCUMENT (g_value_get_object (value)));
+ break;
+ default:
+ G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+ }
+}
+
/**
* ld_canvas_new:
*
@@ -99,3 +171,85 @@ ld_canvas_new (void)
{
return g_object_new (LD_TYPE_CANVAS, NULL);
}
+
+/**
+ * ld_canvas_set_document:
+ * @self: An #LdCanvas object.
+ * @document: The #LdDocument to be assigned to the canvas.
+ *
+ * Assign an #LdDocument object to the canvas.
+ */
+void
+ld_canvas_set_document (LdCanvas *self, LdDocument *document)
+{
+ self->priv->document = document;
+}
+
+/**
+ * ld_canvas_get_document:
+ * @self: An #LdCanvas object.
+ *
+ * Get the #LdDocument object assigned to this canvas.
+ * The reference count on the document is not incremented.
+ */
+LdDocument *
+ld_canvas_get_document (LdCanvas *self)
+{
+ return self->priv->document;
+}
+
+static gboolean
+on_expose_event (GtkWidget *widget, GdkEventExpose *event, gpointer user_data)
+{
+ cairo_t *cr;
+
+ cr = gdk_cairo_create (widget->window);
+
+ cairo_rectangle (cr, event->area.x, event->area.y,
+ event->area.width, event->area.height);
+ cairo_clip (cr);
+
+ canvas_paint (widget, cr);
+
+ cairo_destroy (cr);
+
+ return FALSE;
+}
+
+static void
+draw_grid (GtkWidget *widget, cairo_t *cr)
+{
+ int x, y;
+
+ /* Drawing points:
+ * http://lists.freedesktop.org/archives/cairo/2009-June/017459.html
+ */
+ cairo_set_source_rgb (cr, 0.5, 0.5, 0.5);
+ cairo_set_line_width (cr, 1);
+ cairo_set_line_cap (cr, CAIRO_LINE_CAP_ROUND);
+
+ /* FIXME: Invariable grid size; it's slow because it draws whole area. */
+ for (x = 0; x < widget->allocation.width; x += 20)
+ {
+ for (y = 0; y < widget->allocation.height; y += 20)
+ {
+ /* Drawing sharp lines (also applies to these dots):
+ * http://www.cairographics.org/FAQ/#sharp_lines
+ */
+ cairo_move_to (cr, x + 0.5, y + 0.5);
+ cairo_close_path (cr);
+ cairo_stroke (cr);
+ }
+ }
+}
+
+static void
+canvas_paint (GtkWidget *widget, cairo_t *cr)
+{
+ /* Paint a white background. */
+ cairo_set_source_rgb (cr, 1, 1, 1);
+ cairo_paint (cr);
+
+ draw_grid (widget, cr);
+}
+
diff --git a/src/ld-canvas.h b/src/ld-canvas.h
index 7b6f746..725e243 100644
--- a/src/ld-canvas.h
+++ b/src/ld-canvas.h
@@ -45,7 +45,12 @@ struct _LdCanvas
struct _LdCanvasClass
{
+/*< private >*/
GtkDrawingAreaClass parent_class;
+
+/*
+ void (*set_scroll_adjustments) (GtkAdjustment *x, GtkAdjustment *y);
+*/
};
@@ -53,6 +58,11 @@ GType ld_canvas_get_type (void) G_GNUC_CONST;
LdCanvas *ld_canvas_new (void);
+void ld_canvas_set_document (LdCanvas *self, LdDocument *document);
+LdDocument *ld_canvas_get_document (LdCanvas *self);
+
+/* TODO: The rest of the interface. */
+
G_END_DECLS
diff --git a/src/ld-window-main.c b/src/ld-window-main.c
index 2cecfaa..3713cc9 100644
--- a/src/ld-window-main.c
+++ b/src/ld-window-main.c
@@ -13,8 +13,8 @@
#include "config.h"
#include "ld-window-main.h"
-#include "ld-canvas.h"
#include "ld-document.h"
+#include "ld-canvas.h"
#include "ld-symbol-library.h"
#include "ld-symbol-category.h"
#include "ld-symbol.h"
--
cgit v1.2.3-70-g09d2