Set the canvas scroll region based on the image size.

1999-09-17  Federico Mena Quintero  <federico@redhat.com>

	* ui-image.c (ui_image_set_image): Set the canvas scroll region
	based on the image size.

	* zoom.[ch]: New files with utilitiy functions for computing zoom
	factors.

	* Makefile.am (eog_SOURCES): Added zoom.[ch] to the sources.

	* window.c (WindowPrivate): Added a bin field.  Now we put the
	contents in a simple bin because GnomeApp does not like its
	contents to be removed and added again.
	(window_construct): Create the bin.
	(set_mode): Put the real contents in the bin.

3 files changed, 157 insertions, 1 deletions

diff --git a/libeog/ui-image.c b/libeog/ui-image.c
index 1bf3b00b..1bcc7e87 100644
--- a/libeog/ui-image.c
+++ b/libeog/ui-image.c
@@ -215,6 +215,7 @@ void
 ui_image_set_image (UIImage *ui, Image *image)
 {
 	UIImagePrivate *priv;
+	int w, h;
 
 	g_return_if_fail (ui != NULL);
 	g_return_if_fail (IS_UI_IMAGE (ui));
@@ -236,5 +237,11 @@ ui_image_set_image (UIImage *ui, Image *image)
 			       "image", image,
 			       NULL);
 
-	/* FIXME: set the scroll region and zoom */
+	if (image->buf) {
+		w = image->buf->art_pixbuf->width;
+		h = image->buf->art_pixbuf->height;
+	} else
+		w = h = 0;
+
+	gnome_canvas_set_scroll_region (GNOME_CANVAS (priv->canvas), 0.0, 0.0, w, h);
 }
diff --git a/libeog/zoom.c b/libeog/zoom.c
new file mode 100644
index 00000000..a246b606
--- /dev/null
+++ b/libeog/zoom.c
@@ -0,0 +1,109 @@
+/* Eye of Gnome image viewer - utility functions for computing zoom factors
+ *
+ * Copyright (C) 1999 The Free Software Foundation
+ *
+ * Author: Federico Mena-Quintero <federico@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 2 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include "zoom.h"
+
+
+
+/**
+ * zoom_fit_size:
+ * @dest_width: Width of destination area.
+ * @dest_height: Height of destination area.
+ * @src_width: Width of source image.
+ * @src_height: Height of source image.
+ * @upscale_smaller: Whether to scale up images smaller than the destination size.
+ * @width: Return value for image width.
+ * @height: Return value for image height.
+ * 
+ * Computes the final dimensions of an image that is to be scaled to fit to a
+ * certain size.  If @upscale_smaller is TRUE, then images smaller than the
+ * destination size will be scaled up; otherwise, they will be left at their
+ * original size.
+ **/
+void
+zoom_fit_size (guint dest_width, guint dest_height,
+	       guint src_width, guint src_height,
+	       gboolean upscale_smaller,
+	       guint *width, guint *height)
+{
+	guint w, h;
+
+	g_return_if_fail (width != NULL);
+	g_return_if_fail (height != NULL);
+
+	if (src_width == 0 || src_height == 0) {
+		*width = 0;
+		*height = 0;
+		return;
+	}
+
+	if (src_width <= dest_width && src_height <= dest_height && !upscale_smaller) {
+		*width = src_width;
+		*height = src_height;
+		return;
+	}
+
+	w = dest_width;
+	h = (src_height * w) / src_width;
+
+	if (h > dest_height) {
+		h = dest_height;
+		w = (src_width * h) / src_height;
+	}
+
+	g_assert (w <= dest_width);
+	g_assert (h <= dest_height);
+
+	*width = w;
+	*height = h;
+}
+
+/**
+ * zoom_fit_scale:
+ * @dest_width: Width of destination area.
+ * @dest_height: Height of destination area.
+ * @src_width: Width of source image.
+ * @src_height: Height of source image.
+ * @upscale_smaller: Whether to scale up images smaller than the destination size.
+ * 
+ * Similar to zoom_fit_size(), but returns the zoom factor of the final image
+ * with respect to the original image's size.
+ * 
+ * Return value: Zoom factor with respect to the original size.
+ **/
+double
+zoom_fit_scale (guint dest_width, guint dest_height,
+		guint src_width, guint src_height,
+		gboolean upscale_smaller)
+{
+	guint w, h;
+	double wfactor, hfactor;
+
+	if (src_width == 0 || src_height == 0)
+		return 1.0;
+
+	zoom_fit_size (dest_width, dest_height, src_width, src_height, upscale_smaller, &w, &h);
+
+	wfactor = (double) w / src_width;
+	hfactor = (double) h / src_height;
+
+	return MIN (wfactor, hfactor);
+}
diff --git a/libeog/zoom.h b/libeog/zoom.h
new file mode 100644
index 00000000..73ddfff4
--- /dev/null
+++ b/libeog/zoom.h
@@ -0,0 +1,40 @@
+/* Eye of Gnome image viewer - utility functions for computing zoom factors
+ *
+ * Copyright (C) 1999 The Free Software Foundation
+ *
+ * Author: Federico Mena-Quintero <federico@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 2 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#ifndef ZOOM_H
+#define ZOOM_H
+
+#include <glib.h>
+
+
+
+void zoom_fit_size (guint dest_width, guint dest_height,
+		    guint src_width, guint src_height,
+		    gboolean upscale_smaller,
+		    guint *width, guint *height);
+
+double zoom_fit_scale (guint dest_width, guint dest_height,
+		       guint src_width, guint src_height,
+		       gboolean upscale_smaller);
+
+
+
+#endif