roi: Schedule rubberband drawing to draw-handler

So that we get automatic double buffer handling.

1 files changed, 68 insertions, 79 deletions

diff --git a/roi.c b/roi.c
index d8d9912..91a71ca 100644
--- a/roi.c
+++ b/roi.c
@@ -5,10 +5,6 @@
 #include <gdk-pixbuf/gdk-pixbuf.h>
 #include <gtk/gtk.h>
 
-struct rect {
-	gint x, y, width, height;
-};
-
 struct roi {
 	GtkWidget *window;
 	GtkWidget *drawing_area;
@@ -20,9 +16,12 @@ struct roi {
 
 	GdkPixbuf *input, *modified_input;
 
-	struct rect motion;
-	struct rect roi_area;
-	struct rect previous_draw;
+	cairo_rectangle_t area;
+
+	gboolean doing_rubberband;
+	struct {
+		double x1, y1, x2, y2;
+	} rubberband;
 };
 
 void
@@ -41,17 +40,17 @@ do_roi(struct roi *roi)
 	} interval[3];
 
 	match = gdk_pixbuf_new_subpixbuf(roi->input, 
-					 roi->roi_area.x,
-					 roi->roi_area.y,
-					 roi->roi_area.width,
-					 roi->roi_area.height);
+					 roi->area.x,
+					 roi->area.y,
+					 roi->area.width,
+					 roi->area.height);
 	nch = gdk_pixbuf_get_n_channels(match);
 	stride = gdk_pixbuf_get_rowstride(match);
-	s = roi->roi_area.width * roi->roi_area.height;
+	s = roi->area.width * roi->area.height;
 
 	for (y = 0, row = gdk_pixbuf_get_pixels(match);
-	     y < roi->roi_area.height; ++y, row += stride) {
-		for (x = 0, pix = row; x < roi->roi_area.width; ++x, pix += nch) {
+	     y < roi->area.height; ++y, row += stride) {
+		for (x = 0, pix = row; x < roi->area.width; ++x, pix += nch) {
 			for (i = 0; i < 3; ++i)
 				middle[i] += pix[i];
 		}
@@ -60,8 +59,8 @@ do_roi(struct roi *roi)
 		middle[i] /= s;
 
 	for (y = 0, row = gdk_pixbuf_get_pixels(match);
-	     y < roi->roi_area.height; ++y, row += stride) {
-		for (x = 0, pix = row; x < roi->roi_area.width; ++x, pix += nch) {
+	     y < roi->area.height; ++y, row += stride) {
+		for (x = 0, pix = row; x < roi->area.width; ++x, pix += nch) {
 			for (i = 0; i < 3; ++i)
 				sigma[i] +=
 					(pix[i] - middle[i]) *
@@ -111,49 +110,13 @@ do_roi(struct roi *roi)
 gboolean
 motion_notify_event(GtkWidget *widget, GdkEventMotion *event, gpointer userdata)
 {
-	GtkStyleContext *context;
 	struct roi *roi = userdata;
-	GdkWindow *win = gtk_widget_get_window(widget);
-	cairo_rectangle_t rect;
-	cairo_t *cr;
-
-	rect.x = roi->motion.x;
-	rect.y = roi->motion.y;
-	rect.width = event->x - roi->motion.x;
-	rect.height = event->y - roi->motion.y;
-
-	/* gdk_window_begin_paint_rect(win, &rect); */
-
-	context = gtk_widget_get_style_context(widget);
-	gtk_style_context_save(context);
-	gtk_style_context_add_class(context, GTK_STYLE_CLASS_RUBBERBAND);
 
-	cr = gdk_cairo_create(win);
-	cairo_save(cr);
-	gdk_cairo_set_source_pixbuf(cr, roi->input, 0, 0);
-	cairo_rectangle(cr,
-			roi->previous_draw.x,
-			roi->previous_draw.y,
-			roi->previous_draw.width+1,
-			roi->previous_draw.height+1);
-	cairo_clip(cr);
-	cairo_paint(cr);
-	cairo_restore(cr);
-
-	roi->previous_draw.x = roi->motion.x;
-	roi->previous_draw.y = roi->motion.y;
-	roi->previous_draw.width = event->x - roi->motion.x;
-	roi->previous_draw.height = event->y - roi->motion.y;
-
-	cairo_rectangle(cr, rect.x, rect.y, rect.width, rect.height);
-	cairo_clip(cr);
-	gtk_render_background(context, cr,
-			      rect.x, rect.y, rect.width, rect.height);
-	gtk_render_frame(context, cr, 
-			 rect.x, rect.y, rect.width, rect.height);
-	cairo_destroy(cr);
-	gtk_style_context_restore(context);
-	/* gdk_window_end_paint(win); */
+	if (roi->doing_rubberband) {
+		roi->rubberband.x2 = event->x;
+		roi->rubberband.y2 = event->y;
+		gtk_widget_queue_draw(roi->drawing_area);
+	}
 
 	return TRUE;
 }
@@ -163,13 +126,32 @@ button_press_event(GtkWidget *widget, GdkEventButton *event, gpointer userdata)
 {
 	struct roi *roi = userdata;
 
-	if (event->button != 1)
+	switch (event->button) {
+#ifndef GDK_BUTTON_PRIMARY
+#define GDK_BUTTON_PRIMARY 1
+#endif
+	case GDK_BUTTON_PRIMARY:
+		roi->rubberband.x1 = event->x;
+		roi->rubberband.x2 = event->x;
+		roi->rubberband.y1 = event->y;
+		roi->rubberband.y2 = event->y;
+
+		roi->doing_rubberband = TRUE;
+		return FALSE;
+	default:
 		return TRUE;
+	}
+}
 
-	roi->motion.x = event->x;
-	roi->motion.y = event->y;
-
-	return FALSE;
+static inline void
+calc_rubberband_rect(struct roi *roi,
+		     double *x, double *y,
+		     double *width, double *height)
+{
+	*x = MIN(roi->rubberband.x1, roi->rubberband.x2);
+	*y = MIN(roi->rubberband.y1, roi->rubberband.y2);
+	*width  = ABS(roi->rubberband.x1 - roi->rubberband.x2);
+	*height = ABS(roi->rubberband.y1 - roi->rubberband.y2);
 }
 
 gboolean
@@ -180,25 +162,13 @@ button_release_event(GtkWidget *widget, GdkEventButton *event, gpointer userdata
 	if (event->button != 1)
 		return TRUE;
 
-	roi->roi_area.x = roi->motion.x;
-	roi->roi_area.y = roi->motion.y;
-	roi->roi_area.width = event->x - roi->motion.x;
-	roi->roi_area.height = event->y - roi->motion.y;
-
-	if (roi->roi_area.width < 0) {
-		roi->roi_area.x -= roi->roi_area.width;
-		roi->roi_area.width = -roi->roi_area.width;
-	}
-
-	if (roi->roi_area.height < 0) {
-		roi->roi_area.y -= roi->roi_area.height;
-		roi->roi_area.height = -roi->roi_area.height;
-	}
+	calc_rubberband_rect(roi, &roi->area.x, &roi->area.y, 
+			     &roi->area.width, &roi->area.height);
 
-	if (roi->roi_area.width != 0 &&
-	    roi->roi_area.height != 0)
+	if (roi->area.width > 0 && roi->area.height > 0)
 		do_roi(roi);
-	roi->previous_draw.width = roi->previous_draw.height = 0;
+
+	roi->doing_rubberband = FALSE;
 
 	gtk_widget_queue_draw(roi->drawing_area);
 
@@ -235,6 +205,22 @@ configure_event(GtkWidget *widget, GdkEventConfigure *event, gpointer data)
 	return FALSE;
 }
 
+void
+draw_rubberband(struct roi *roi, GtkWidget *widget, cairo_t *cr)
+{
+	GtkStyleContext *context;
+	double x, y, width, height;
+
+	context = gtk_widget_get_style_context(widget);
+	gtk_style_context_save(context);
+	gtk_style_context_add_class(context, GTK_STYLE_CLASS_RUBBERBAND);
+
+	calc_rubberband_rect(roi, &x, &y, &width, &height);
+	gtk_render_background(context, cr, x, y, width, height);
+	gtk_render_frame(context, cr, x, y, width, height);
+	gtk_style_context_restore(context);
+}
+
 gboolean
 draw_cb(GtkWidget *widget, cairo_t *cr, gpointer userdata)
 {
@@ -244,6 +230,9 @@ draw_cb(GtkWidget *widget, cairo_t *cr, gpointer userdata)
 				    roi->modified_input : roi->input, 0, 0);
 	cairo_paint(cr);
 
+	if (roi->doing_rubberband)
+		draw_rubberband(roi, widget, cr);
+
 	return FALSE;
 }