From e9a35b1958c7faecb50ee33b88d79c45c44c38e5 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Tue, 13 Aug 2013 13:16:02 +0530
Subject: [PATCH] Show current aspect ratio when changing cover size

---
 src/calibre/gui2/preferences/look_feel.py | 15 ++++++++++++++-
 src/calibre/gui2/preferences/look_feel.ui | 13 +++++++++++--
 2 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/src/calibre/gui2/preferences/look_feel.py b/src/calibre/gui2/preferences/look_feel.py
index 27ca36d0a1..469eaf35cb 100644
--- a/src/calibre/gui2/preferences/look_feel.py
+++ b/src/calibre/gui2/preferences/look_feel.py
@@ -222,8 +222,11 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
         self.cover_grid_larger_cover.clicked.connect(partial(self.resize_cover, False))
         self.opt_cover_grid_disk_cache_size.setMinimum(self.gui.grid_view.thumbnail_cache.min_disk_cache)
         self.opt_cover_grid_disk_cache_size.setMaximum(self.gui.grid_view.thumbnail_cache.min_disk_cache * 100)
+        self.opt_cover_grid_width.valueChanged.connect(self.update_aspect_ratio)
+        self.opt_cover_grid_height.valueChanged.connect(self.update_aspect_ratio)
 
-    def resize_cover(self, smaller):
+    @property
+    def current_cover_size(self):
         cval = self.opt_cover_grid_height.value()
         wval = self.opt_cover_grid_width.value()
         if cval < 0.1:
@@ -231,6 +234,15 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
             cval = auto_height(self.opt_cover_grid_height) / dpi / CM_TO_INCH
         if wval < 0.1:
             wval = 0.75 * cval
+        return wval, cval
+
+    def update_aspect_ratio(self, *args):
+        width, height = self.current_cover_size
+        ar = width / height
+        self.cover_grid_aspect_ratio.setText(_('Current aspect ratio (width/height): %.2g') % ar)
+
+    def resize_cover(self, smaller):
+        wval, cval = self.current_cover_size
         ar = wval / cval
         delta = 0.2 * (-1 if smaller else 1)
         cval += delta
@@ -256,6 +268,7 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
         self.edit_rules.initialize(db.field_metadata, db.prefs, mi, 'column_color_rules')
         self.icon_rules.initialize(db.field_metadata, db.prefs, mi, 'column_icon_rules')
         self.set_cg_color(gprefs['cover_grid_color'])
+        self.update_aspect_ratio()
 
     def open_cg_cache(self):
         open_local_file(self.gui.grid_view.thumbnail_cache.location)
diff --git a/src/calibre/gui2/preferences/look_feel.ui b/src/calibre/gui2/preferences/look_feel.ui
index 1adda76634..45874a095f 100644
--- a/src/calibre/gui2/preferences/look_feel.ui
+++ b/src/calibre/gui2/preferences/look_feel.ui
@@ -380,7 +380,8 @@
           <item row="1" column="1">
            <widget class="QDoubleSpinBox" name="opt_cover_grid_width">
             <property name="toolTip">
-             <string>The width of displayed covers</string>
+             <string>The width of displayed covers.
+A value of zero means calculate automatically.</string>
             </property>
             <property name="specialValueText">
              <string>Automatic</string>
@@ -420,7 +421,8 @@
           <item row="2" column="1">
            <widget class="QDoubleSpinBox" name="opt_cover_grid_height">
             <property name="toolTip">
-             <string>The height of displayed covers</string>
+             <string>The height of displayed covers.
+A value of zero means calculate automatically.</string>
             </property>
             <property name="specialValueText">
              <string>Automatic</string>
@@ -470,6 +472,13 @@
             </property>
            </widget>
           </item>
+          <item row="3" column="0" colspan="4">
+           <widget class="QLabel" name="cover_grid_aspect_ratio">
+            <property name="text">
+             <string/>
+            </property>
+           </widget>
+          </item>
          </layout>
         </widget>
        </item>