Add option to disable Wintab from Preferences dialog

With this is easier to give support to the end-user. The
--disable-wintab option was initially added for crash situation when
the user cannot execute Aseprite from the very beginning, but in other
situations, when Aseprite can be executed correctly but the stylus
doesn't work as expected, it's nice to have this option available from
the UI just to disable the Wintab32.dll.

data/pref.xml

@@ -155,6 +155,7 @@
       <option id="use_native_clipboard" type="bool" default="true" />
       <option id="use_native_file_dialog" type="bool" default="false" />
       <option id="one_finger_as_mouse_movement" type="bool" default="true" />
+      <option id="load_wintab_driver" type="bool" default="true" />
       <option id="flash_layer" type="bool" default="false" migrate="Options.FlashLayer" />
       <option id="nonactive_layers_opacity" type="int" default="255" />
     </section>

data/strings/en.ini

@@ -1019,10 +1019,16 @@ one_finger_as_mouse_movement_tooltip = <<<END
 Only for Windows 8/10 tablets: Interprets one finger as mouse movement
 and two fingers as pan/scroll. Uncheck this to use the old behavior:
 One finger pans/scrolls.
-
-This option is available just to get the old behavior but
+--
+Note: This option is available just to get the old behavior but
 will be removed in future versions.
 END
+load_wintab_driver = Load wintab32 library
+load_wintab_driver_tooltip = <<<END
+Loads wintab32.dll driver to use Wacom-like devices
+when Aseprite is started.
+END
+wintab_more_info = (More Information)
 flash_selected_layer = Flash layer when it is selected
 non_active_layer_opacity = Opacity for non-active layers:
 ok = &OK

data/widgets/options.xml

@@ -367,6 +367,13 @@
                  text="@.one_finger_as_mouse_movement"
                  tooltip="@.one_finger_as_mouse_movement_tooltip"
                  pref="experimental.one_finger_as_mouse_movement" />
+	  <hbox id="load_wintab_driver_box">
+            <check id="load_wintab_driver"
+                   text="@.load_wintab_driver"
+                   tooltip="@.load_wintab_driver_tooltip"
+                   pref="experimental.load_wintab_driver" />
+            <link text="@.wintab_more_info" url="https://www.aseprite.org/docs/wintab/" />
+          </hbox>
           <check id="flash_layer" text="@.flash_selected_layer" />
           <hbox>
             <label text="@.non_active_layer_opacity" />

src/app/app.cpp

@@ -176,11 +176,6 @@ App::App()
 
 void App::initialize(const AppOptions& options)
 {
-#ifdef _WIN32
-  if (options.disableWintab())
-    she::instance()->useWintabAPI(false);
-#endif
-
 #ifdef ENABLE_UI
   m_isGui = options.startUI() && !options.previewCLI();
 #else
@@ -188,6 +183,14 @@ void App::initialize(const AppOptions& options)
 #endif
   m_isShell = options.startShell();
   m_coreModules = new CoreModules;
+
+#ifdef _WIN32
+  if (options.disableWintab() ||
+      !preferences().experimental.loadWintabDriver()) {
+    she::instance()->useWintabAPI(false);
+  }
+#endif
+
   if (m_isGui)
     m_uiSystem.reset(new ui::UISystem);
 

src/app/commands/cmd_options.cpp

@@ -246,6 +246,7 @@ public:
 
 #ifndef _WIN32
     oneFingerAsMouseMovement()->setVisible(false);
+    loadWintabDriverBox()->setVisible(false);
 #endif
 
     if (m_pref.experimental.flashLayer())