Bug 645725 - Don't require two taps to open non-fullscreen Android keyboards [r=mfinkle]

mobile/chrome/content/browser-ui.js

@@ -297,8 +297,8 @@ var BrowserUI = {
     if (this._activePanel)
       this._activePanel.close();
 
-    // The readOnly state of the field enabled/disabled the VKB
-    let isReadOnly = !(aPanel == AllPagesList && Util.isPortrait() && (willShowPanel || !this._edit.readOnly));
+    // If the keyboard will cover the full screen, we do not want to show it right away.
+    let isReadOnly = (aPanel != AllPagesList || this._isKeyboardFullscreen() || (!willShowPanel && this._edit.readOnly));
     this._edit.readOnly = isReadOnly;
     if (isReadOnly)
       this._edit.blur();
@@ -355,6 +355,24 @@ var BrowserUI = {
     this._dispatchPopupChanged(false);
   },
 
+  // Will the on-screen keyboard cover the whole screen when opened?
+  _isKeyboardFullscreen: function _isKeyboardFullscreen() {
+#ifdef ANDROID
+    if (!Util.isPortrait()) {
+      switch (Services.prefs.getIntPref("widget.ime.android.landscape_fullscreen")) {
+        case 1:
+          return true;
+        case -1: {
+          let threshold = Services.prefs.getIntPref("widget.ime.android.fullscreen_threshold");
+          let dpi = Util.getWindowUtils(window).displayDPI;
+          return (window.innerHeight * 100 < threshold * dpi);
+        }
+      }
+    }
+#endif
+    return false;
+  },
+
   _dispatchPopupChanged: function _dispatchPopupChanged(aVisible) {
     let stack = document.getElementById("stack");
     let event = document.createEvent("UIEvents");