Add a preference to turn high DPI scaling on or off

src/calibre/gui2/__init__.py

@@ -148,6 +148,7 @@ def create_defs():
     defs['metadata_diff_mark_rejected'] = False
     defs['tag_browser_show_counts'] = True
     defs['row_numbers_in_book_list'] = True
+    defs['hidpi'] = 'auto'
 
 
 create_defs()
@@ -938,17 +939,28 @@ class Application(QApplication):
         self.headless = headless
         qargs = [i.encode('utf-8') if isinstance(i, unicode) else i for i in args]
         self.pi = plugins['progress_indicator'][0]
-        if not isosx and not headless and hasattr(Qt, 'AA_EnableHighDpiScaling'):
+        if not isosx and not headless:
             # On OS X high dpi scaling is turned on automatically by the OS, so we dont need to set it explicitly
             # This requires Qt >= 5.6
-            for v in ('QT_AUTO_SCREEN_SCALE_FACTOR', 'QT_SCALE_FACTOR', 'QT_SCREEN_SCALE_FACTORS', 'QT_DEVICE_PIXEL_RATIO'):
+            has_env_setting = False
+            env_vars = ('QT_AUTO_SCREEN_SCALE_FACTOR', 'QT_SCALE_FACTOR', 'QT_SCREEN_SCALE_FACTORS', 'QT_DEVICE_PIXEL_RATIO')
+            for v in env_vars:
                 if os.environ.get(v):
+                    has_env_setting = True
                     break
-            else:
-                # Should probably make a preference to allow the user to
-                # control this, if needed.
-                # Could have options: auto, off, 1.25, 1.5, 1.75, 2, 2.25, 2.5
+            hidpi = gprefs['hidpi']
+            if hidpi == 'on' or (hidpi == 'auto' and not has_env_setting):
+                if DEBUG:
+                    prints('Turning on hidpi scaling')
                 QApplication.setAttribute(Qt.AA_EnableHighDpiScaling, True)
+            elif hidpi == 'off':
+                if DEBUG:
+                    prints('Turning off hidpi scaling')
+                QApplication.setAttribute(Qt.AA_EnableHighDpiScaling, False)
+                for p in env_vars:
+                    os.environ.pop(p, None)
+            elif DEBUG:
+                prints('Not controlling hidpi scaling')
         QApplication.setOrganizationName('calibre-ebook.com')
         QApplication.setOrganizationDomain(QApplication.organizationName())
         QApplication.setApplicationVersion(__version__)

src/calibre/gui2/preferences/look_feel.py

@@ -20,6 +20,7 @@ from PyQt5.Qt import (
 
 from calibre import human_readable
 from calibre.ebooks.metadata.book.render import DEFAULT_AUTHOR_LINK
+from calibre.constants import isosx
 from calibre.ebooks.metadata.sources.prefs import msprefs
 from calibre.gui2 import default_author_link
 from calibre.gui2.dialogs.template_dialog import TemplateDialog
@@ -338,8 +339,10 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
         self.default_author_link = DefaultAuthorLink(self.default_author_link_container)
         self.default_author_link.changed_signal.connect(self.changed_signal)
         r('gui_layout', config, restart_required=True, choices=[(_('Wide'), 'wide'), (_('Narrow'), 'narrow')])
-        r('ui_style', gprefs, restart_required=True, choices=[(_('System default'), 'system'), (_('calibre style'),
-                    'calibre')])
+        r('hidpi', gprefs, restart_required=True, choices=[(_('Automatic'), 'auto'), (_('On'), 'on'), (_('Off'), 'off')])
+        if isosx:
+            self.opt_hidpi.setVisible(False), self.label_hidpi.setVisible(False)
+        r('ui_style', gprefs, restart_required=True, choices=[(_('System default'), 'system'), (_('calibre style'), 'calibre')])
         r('book_list_tooltips', gprefs)
         r('row_numbers_in_book_list', gprefs)
         r('tag_browser_old_look', gprefs, restart_required=True)

src/calibre/gui2/preferences/look_feel.ui

@@ -28,7 +28,17 @@
        <string>&amp;Main interface</string>
       </attribute>
       <layout class="QGridLayout" name="gridLayout_9">
-       <item row="9" column="0">
+       <item row="2" column="0">
+        <widget class="QLabel" name="label_17">
+         <property name="text">
+          <string>&amp;User Interface layout (needs restart):</string>
+         </property>
+         <property name="buddy">
+          <cstring>opt_gui_layout</cstring>
+         </property>
+        </widget>
+       </item>
+       <item row="10" column="0">
         <widget class="QLabel" name="label_4">
          <property name="text">
           <string>E&amp;xtra spacing to add between rows in the book list (can be negative):</string>
@@ -38,7 +48,7 @@
          </property>
         </widget>
        </item>
-       <item row="9" column="1">
+       <item row="10" column="1">
         <widget class="QSpinBox" name="opt_book_list_extra_row_spacing">
          <property name="suffix">
           <string> px</string>
@@ -48,7 +58,7 @@
          </property>
         </widget>
        </item>
-       <item row="8" column="0" colspan="2">
+       <item row="9" column="0" colspan="2">
         <widget class="QGroupBox" name="groupBox_2">
          <property name="title">
           <string>&amp;Toolbar</string>
@@ -86,7 +96,7 @@
        <item row="0" column="1">
         <widget class="QComboBox" name="opt_ui_style"/>
        </item>
-       <item row="7" column="1">
+       <item row="8" column="1">
         <widget class="QPushButton" name="change_font_button">
          <property name="text">
           <string>Change &amp;font (needs restart)</string>
@@ -109,14 +119,14 @@
          </property>
         </widget>
        </item>
-       <item row="6" column="0">
+       <item row="7" column="0">
         <widget class="QCheckBox" name="opt_book_list_tooltips">
          <property name="text">
           <string>Show &amp;tooltips in the book list</string>
          </property>
         </widget>
        </item>
-       <item row="11" column="0">
+       <item row="12" column="0">
         <spacer name="verticalSpacer_3">
          <property name="orientation">
           <enum>Qt::Vertical</enum>
@@ -129,7 +139,7 @@
          </property>
         </spacer>
        </item>
-       <item row="4" column="0">
+       <item row="5" column="0">
         <widget class="QCheckBox" name="opt_systray_icon">
          <property name="text">
           <string>Enable system &amp;tray icon (needs restart)</string>
@@ -146,7 +156,7 @@
          </property>
         </widget>
        </item>
-       <item row="7" column="0">
+       <item row="8" column="0">
         <layout class="QHBoxLayout" name="horizontalLayout">
          <item>
           <widget class="QLabel" name="label_2">
@@ -174,7 +184,7 @@
          </property>
         </widget>
        </item>
-       <item row="5" column="0">
+       <item row="6" column="0">
         <widget class="QCheckBox" name="opt_disable_tray_notification">
          <property name="text">
           <string>Disable &amp;notifications in system tray</string>
@@ -201,17 +211,7 @@
          </property>
         </widget>
        </item>
-       <item row="2" column="0">
-        <widget class="QLabel" name="label_17">
-         <property name="text">
-          <string>&amp;User Interface layout (needs restart):</string>
-         </property>
-         <property name="buddy">
-          <cstring>opt_gui_layout</cstring>
-         </property>
-        </widget>
-       </item>
-       <item row="4" column="1">
+       <item row="5" column="1">
         <widget class="QCheckBox" name="opt_disable_animations">
          <property name="toolTip">
           <string>Disable all animations. Useful if you have a slow/old computer.</string>
@@ -221,7 +221,7 @@
          </property>
         </widget>
        </item>
-       <item row="5" column="1">
+       <item row="6" column="1">
         <widget class="QCheckBox" name="opt_show_splash_screen">
          <property name="text">
           <string>Show &amp;splash screen at startup</string>
@@ -235,13 +235,35 @@
          </property>
         </widget>
        </item>
-       <item row="10" column="0">
+       <item row="11" column="0">
         <widget class="QCheckBox" name="opt_row_numbers_in_book_list">
          <property name="text">
           <string>Show &amp;row numbers in the book list</string>
          </property>
         </widget>
        </item>
+       <item row="4" column="0">
+        <widget class="QLabel" name="label_hidpi">
+         <property name="text">
+          <string>Adjust for high resolution screens (needs restart):</string>
+         </property>
+        </widget>
+       </item>
+       <item row="4" column="1">
+        <widget class="QComboBox" name="opt_hidpi">
+         <property name="toolTip">
+          <string>&lt;p&gt;Whether to automatically adjust the calibre user interface for high resolution (high DPI) monitors. There are three possible values:&lt;/p&gt;
+
+&lt;ul&gt;
+&lt;li&gt;&lt;b&gt;Automatic&lt;/b&gt;: Adjust the user interface if a high resolution monitor is detected. Will respect Qt environment variables controlling high DPI behavior. So if you use the environment variable QT_AUTO_SCREEN_SCALE_FACTOR then it will be used instead of this setting.&lt;/li&gt;
+
+&lt;li&gt;&lt;b&gt;On&lt;/b&gt;: Same as &quot;Automatic&quot;, but ignores Qt environment variables controlling high dpi behavior.&lt;/li&gt;
+
+&lt;li&gt;&lt;b&gt;Off&lt;/b&gt;: Do not adjust the user interface, regardless of Qt environment variables.&lt;/li&gt;
+&lt;/ul&gt;</string>
+         </property>
+        </widget>
+       </item>
       </layout>
      </widget>
      <widget class="QWidget" name="cover_grid_tab">