Built a system for doing selections and/or a cursor in canvas.

2000-06-20  Christopher James Lahey  <clahey@helixcode.com>

	* e-canvas.c, e-canvas.h: Built a system for doing selections
	and/or a cursor in canvas.

svn path=/trunk/; revision=3655

2 files changed, 159 insertions, 3 deletions

diff --git a/widgets/misc/e-canvas.c b/widgets/misc/e-canvas.c
index 534e3fb1e8..230d5a72ea 100644
--- a/widgets/misc/e-canvas.c
+++ b/widgets/misc/e-canvas.c
@@ -45,6 +45,11 @@ enum {
 
 static guint e_canvas_signals [LAST_SIGNAL] = { 0, };
 
+typedef struct {
+	GnomeCanvasItem *item;
+	gpointer         id;
+} ECanvasSelectionInfo;
+
 GtkType
 e_canvas_get_type (void)
 {
@@ -107,6 +112,7 @@ e_canvas_class_init (ECanvasClass *klass)
 static void
 e_canvas_init (ECanvas *canvas)
 {
+	canvas->selection = NULL;
 }
 
 static void
@@ -458,3 +464,126 @@ e_canvas_item_set_reflow_callback (GnomeCanvasItem *item, ECanvasItemReflowFunc
 {
 	gtk_object_set_data(GTK_OBJECT(item), "ECanvasItem::reflow_callback", (gpointer) func);
 }
+
+
+void
+e_canvas_item_set_selection_callback (GnomeCanvasItem *item, ECanvasItemSelectionFunc func)
+{
+	gtk_object_set_data(GTK_OBJECT(item), "ECanvasItem::selection_callback", (gpointer) func);
+}
+
+void
+e_canvas_item_set_selection_compare_callback (GnomeCanvasItem *item, ECanvasItemSelectionCompareFunc func)
+{
+	gtk_object_set_data(GTK_OBJECT(item), "ECanvasItem::selection_compare_callback", (gpointer) func);
+}
+
+void
+e_canvas_item_set_cursor (GnomeCanvasItem *item, gpointer id)
+{
+	GList *list;
+	int flags;
+	ECanvas *canvas;
+	ECanvasSelectionInfo *info;
+	ECanvasItemSelectionFunc func;
+
+	g_return_if_fail(item != NULL);
+	g_return_if_fail(GNOME_IS_CANVAS_ITEM(item));
+	g_return_if_fail(item->canvas != NULL);
+	g_return_if_fail(E_IS_CANVAS(item->canvas));
+
+	canvas = E_CANVAS(item->canvas);
+	flags = E_CANVAS_ITEM_SELECTION_DELETE_DATA;
+
+	for (list = canvas->selection; list; list = g_list_next(list)) {
+		info = list->data;
+
+		func = gtk_object_get_data(GTK_OBJECT(info->item), "ECanvasItem::selection_callback");
+		if (func)
+			func(info->item, flags, info->id);
+		g_free(info);
+	}
+	g_list_free(canvas->selection);
+
+	canvas->selection = NULL;
+	
+	info = g_new(ECanvasSelectionInfo, 1);
+	info->item = item;
+	info->id = id;
+	
+	flags = E_CANVAS_ITEM_SELECTION_SELECT | E_CANVAS_ITEM_SELECTION_CURSOR;
+	func = gtk_object_get_data(GTK_OBJECT(item), "ECanvasItem::selection_callback");
+	if (func)
+		func(item, flags, id);
+	
+	canvas->selection = g_list_prepend(canvas->selection, info);
+}
+
+void
+e_canvas_item_set_cursor_end (GnomeCanvasItem *item, gpointer id)
+{
+}
+
+void
+e_canvas_item_add_selection (GnomeCanvasItem *item, gpointer id)
+{
+	int flags;
+	ECanvas *canvas;
+	ECanvasSelectionInfo *info;
+	ECanvasItemSelectionFunc func;
+
+	g_return_if_fail(item != NULL);
+	g_return_if_fail(GNOME_IS_CANVAS_ITEM(item));
+	g_return_if_fail(item->canvas != NULL);
+	g_return_if_fail(E_IS_CANVAS(item->canvas));
+
+	flags = E_CANVAS_ITEM_SELECTION_SELECT | E_CANVAS_ITEM_SELECTION_CURSOR;
+	canvas = E_CANVAS(item->canvas);
+
+	info = g_new(ECanvasSelectionInfo, 1);
+	info->item = item;
+	info->id = id;
+
+	func = gtk_object_get_data(GTK_OBJECT(item), "ECanvasItem::selection_callback");
+	if (func)
+		func(item, flags, id);
+	
+	canvas->selection = g_list_prepend(canvas->selection, info);
+}
+
+void
+e_canvas_item_remove_selection (GnomeCanvasItem *item, gpointer id)
+{
+	int flags;
+	ECanvas *canvas;
+	ECanvasSelectionInfo *info;
+	GList *list;
+
+	g_return_if_fail(item != NULL);
+	g_return_if_fail(GNOME_IS_CANVAS_ITEM(item));
+	g_return_if_fail(item->canvas != NULL);
+	g_return_if_fail(E_IS_CANVAS(item->canvas));
+
+	flags = E_CANVAS_ITEM_SELECTION_DELETE_DATA;
+	canvas = E_CANVAS(item->canvas);
+
+	for (list = canvas->selection; list; list = g_list_next(list)) {
+		info = list->data;
+		
+		if (info->item == item) {
+			ECanvasItemSelectionCompareFunc compare_func;
+			compare_func = gtk_object_get_data(GTK_OBJECT(info->item), "ECanvasItem::selection_compare_callback");
+			if (compare_func(info->item, info->id, id, 0) == 0) {
+				ECanvasItemSelectionFunc func;
+				func = gtk_object_get_data(GTK_OBJECT(info->item), "ECanvasItem::selection_callback");
+				if (func)
+					func(info->item, flags, info->id);
+				canvas->selection = g_list_remove_link(canvas->selection, list);
+				g_free(info);
+				g_list_free_1(list);
+				break;
+			}
+		}
+	}
+}
+
diff --git a/widgets/misc/e-canvas.h b/widgets/misc/e-canvas.h
index f1ff1195c9..9e572a1179 100644
--- a/widgets/misc/e-canvas.h
+++ b/widgets/misc/e-canvas.h
@@ -41,6 +41,16 @@ extern "C" {
 typedef void		(*ECanvasItemReflowFunc)		(GnomeCanvasItem *item,
 								 gint   	  flags);
 
+typedef void            (*ECanvasItemSelectionFunc)             (GnomeCanvasItem *item,
+								 gint             flags,
+								 gpointer         user_data);
+/* Returns the same as strcmp does. */
+typedef gint            (*ECanvasItemSelectionCompareFunc)      (GnomeCanvasItem *item,
+								 gpointer         data1,
+								 gpointer         data2,
+								 gint             flags);
+
+
 typedef struct _ECanvas       ECanvas;
 typedef struct _ECanvasClass  ECanvasClass;
 
@@ -50,11 +60,18 @@ enum {
 	E_CANVAS_ITEM_DESCENDENT_NEEDS_REFLOW = 1 << 14
 };
 
+enum {
+	E_CANVAS_ITEM_SELECTION_SELECT        = 1 << 0, /* TRUE = select.  FALSE = unselect. */
+	E_CANVAS_ITEM_SELECTION_CURSOR        = 1 << 1, /* TRUE = has become cursor.  FALSE = not cursor. */
+	E_CANVAS_ITEM_SELECTION_DELETE_DATA   = 1 << 2,
+};
+
 struct _ECanvas
 {
-	GnomeCanvas parent;
-	
-	int         idle_id;	
+	GnomeCanvas  parent;
+
+	int          idle_id;
+	GList       *selection;
 };
 
 struct _ECanvasClass
@@ -76,6 +93,16 @@ void e_canvas_item_request_reflow (GnomeCanvasItem *item);
 void e_canvas_item_request_parent_reflow (GnomeCanvasItem *item);
 void e_canvas_item_set_reflow_callback (GnomeCanvasItem *item, ECanvasItemReflowFunc func);
 
+void e_canvas_item_set_selection_callback (GnomeCanvasItem *item, ECanvasItemSelectionFunc func);
+void e_canvas_item_set_selection_compare_callback (GnomeCanvasItem *item, ECanvasItemSelectionCompareFunc func);
+
+void e_canvas_item_set_cursor (GnomeCanvasItem *item, gpointer id);
+void e_canvas_item_add_selection (GnomeCanvasItem *item, gpointer id);
+void e_canvas_item_remove_selection (GnomeCanvasItem *item, gpointer id);
+
+/* Not implemented yet. */
+void e_canvas_item_set_cursor_end (GnomeCanvasItem *item, gpointer id);
+
 #ifdef __cplusplus
 }
 #endif /* __cplusplus */