From 9cb35383a8a942524949899e18b1fea057fea68a Mon Sep 17 00:00:00 2001
From: Axel Wagner <mail@merovius.de>
Date: Sat, 13 Mar 2010 10:38:22 +0100
Subject: [PATCH] Implement proportional floating-resize.

---
 include/floating.h |  2 +-
 src/click.c        |  3 ++-
 src/floating.c     | 44 ++++++++++++++++++++++++++++----------------
 3 files changed, 31 insertions(+), 18 deletions(-)

diff --git a/include/floating.h b/include/floating.h
index d368048b..aa9d9d5f 100644
--- a/include/floating.h
+++ b/include/floating.h
@@ -71,7 +71,7 @@ void floating_drag_window(xcb_connection_t *conn, Client *client,
  *
  */
 void floating_resize_window(xcb_connection_t *conn, Client *client,
-                            xcb_button_press_event_t *event);
+                            bool proportional, xcb_button_press_event_t *event);
 
 /**
  * Changes focus in the given direction for floating clients.
diff --git a/src/click.c b/src/click.c
index d792ce23..bec86788 100644
--- a/src/click.c
+++ b/src/click.c
@@ -280,8 +280,9 @@ int handle_button_press(void *ignored, xcb_connection_t *conn, xcb_button_press_
                                 DLOG("left mouse button, dragging\n");
                                 floating_drag_window(conn, client, event);
                         } else if (event->detail == 3) {
+                                bool proportional = (event->state & BIND_SHIFT);
                                 DLOG("right mouse button\n");
-                                floating_resize_window(conn, client, event);
+                                floating_resize_window(conn, client, proportional, event);
                         }
                         return 1;
                 }
diff --git a/src/floating.c b/src/floating.c
index 0d97c27a..61e95599 100644
--- a/src/floating.c
+++ b/src/floating.c
@@ -291,6 +291,7 @@ void floating_drag_window(xcb_connection_t *conn, Client *client, xcb_button_pre
  */
 struct resize_window_callback_params {
         border_t corner;
+        bool proportional;
         xcb_button_press_event_t *event;
 };
 
@@ -304,27 +305,37 @@ DRAGGING_CB(resize_window_callback) {
         uint32_t dest_width;
         uint32_t dest_height;
 
-        if (corner & BORDER_LEFT) {
-                dest_x = old_rect->x + (new_x - event->root_x);
+        double ratio = (double) old_rect->width / old_rect->height;
+
+        /* First guess: We resize by exactly the amount the mouse moved,
+         * taking into account in which corner the client was grabbed */
+        if (corner & BORDER_LEFT)
                 dest_width = old_rect->width - (new_x - event->root_x);
-        } else dest_width = old_rect->width + (new_x - event->root_x);
+        else dest_width = old_rect->width + (new_x - event->root_x);
 
-        if (corner & BORDER_TOP) {
-                dest_y = old_rect->y + (new_y - event->root_y);
+        if (corner & BORDER_TOP)
                 dest_height = old_rect->height - (new_y - event->root_y);
-        } else dest_height = old_rect->height + (new_y - event->root_y);
+        else dest_height = old_rect->height + (new_y - event->root_y);
 
+        /* Obey minimum window size */
+        dest_width = max(dest_width, client_min_width(client));
+        dest_height = max(dest_height, client_min_height(client));
 
-        /* Obey minimum window size and reposition the client */
-        if (dest_width > 0 && dest_width >= client_min_width(client)) {
-                client->rect.x = dest_x;
-                client->rect.width = dest_width;
+        /* User wants to keep proportions, so we may have to adjust our values */
+        if (params->proportional) {
+                dest_width = max(dest_width, (int) (dest_height * ratio));
+                dest_height = max(dest_height, (int) (dest_width / ratio));
         }
 
-        if (dest_height > 0 && dest_height >= client_min_height(client)) {
-                client->rect.y = dest_y;
-                client->rect.height = dest_height;
-        }
+        /* If not the lower right corner is grabbed, we must also reposition
+         * the client by exactly the amount we resized it */
+        if (corner & BORDER_LEFT)
+                dest_x = old_rect->x + (old_rect->width - dest_width);
+
+        if (corner & BORDER_TOP)
+                dest_y = old_rect->y + (old_rect->height - dest_height);
+
+        client->rect = (Rect) { dest_x, dest_y, dest_width, dest_height };
 
         /* resize_client flushes */
         resize_client(conn, client);
@@ -336,7 +347,8 @@ DRAGGING_CB(resize_window_callback) {
  * Calls the drag_pointer function with the resize_window callback
  *
  */
-void floating_resize_window(xcb_connection_t *conn, Client *client, xcb_button_press_event_t *event) {
+void floating_resize_window(xcb_connection_t *conn, Client *client,
+                            bool proportional, xcb_button_press_event_t *event) {
         DLOG("floating_resize_window\n");
 
         /* corner saves the nearest corner to the original click. It contains
@@ -351,7 +363,7 @@ void floating_resize_window(xcb_connection_t *conn, Client *client, xcb_button_p
                 corner |= BORDER_TOP;
         else corner |= BORDER_RIGHT;
 
-        struct resize_window_callback_params params = { corner, event };
+        struct resize_window_callback_params params = { corner, proportional, event };
 
         drag_pointer(conn, client, event, XCB_NONE, BORDER_TOP /* irrelevant */, resize_window_callback, &params);
 }
-- 
2.39.5