Add support for force-enabling zoom

Adds an option in WebSettings that causes WebView to ignore the
 user-scalable option on the viewport metatag

Change-Id: Ia850489811a6617a8c17ec6cb17e0a65400f55f0

core/java/android/webkit/WebSettings.java

@@ -219,6 +219,7 @@ public class WebSettings {
     private boolean         mAllowContentAccess = true;
     private boolean         mLoadWithOverviewMode = false;
     private boolean         mEnableSmoothTransition = false;
+    private boolean         mForceUserScalable = false;
 
     // AutoFill Profile data
     /**
@@ -1658,6 +1659,23 @@ public class WebSettings {
         }
     }
 
+    /**
+     * Returns whether the viewport metatag can disable zooming
+     * @hide
+     */
+    public boolean forceUserScalable() {
+        return mForceUserScalable;
+    }
+
+    /**
+     * Sets whether viewport metatag can disable zooming.
+     * @param flag Whether or not to forceably enable user scalable.
+     * @hide
+     */
+    public synchronized void setForceUserScalable(boolean flag) {
+        mForceUserScalable = flag;
+    }
+
     synchronized void setSyntheticLinksEnabled(boolean flag) {
         if (mSyntheticLinksEnabled != flag) {
             mSyntheticLinksEnabled = flag;

core/java/android/webkit/WebViewCore.java

@@ -2253,6 +2253,27 @@ final class WebViewCore {
         // set the viewport settings from WebKit
         setViewportSettingsFromNative();
 
+        if (mSettings.forceUserScalable()) {
+            mViewportUserScalable = true;
+            if (mViewportInitialScale > 0) {
+                if (mViewportMinimumScale > 0) {
+                    mViewportMinimumScale = Math.min(mViewportMinimumScale,
+                            mViewportInitialScale / 2);
+                }
+                if (mViewportMaximumScale > 0) {
+                    mViewportMaximumScale = Math.max(mViewportMaximumScale,
+                            mViewportInitialScale * 2);
+                }
+            } else {
+                if (mViewportMinimumScale > 0) {
+                    mViewportMinimumScale = Math.min(mViewportMinimumScale, 50);
+                }
+                if (mViewportMaximumScale > 0) {
+                    mViewportMaximumScale = Math.max(mViewportMaximumScale, 200);
+                }
+            }
+        }
+
         // adjust the default scale to match the densityDpi
         float adjust = 1.0f;
         if (mViewportDensityDpi == -1) {
@@ -2589,11 +2610,11 @@ final class WebViewCore {
 
     // called by JNI
     private Class<?> getPluginClass(String libName, String clsName) {
-        
+
         if (mWebView == null) {
             return null;
         }
-        
+
         PluginManager pluginManager = PluginManager.getInstance(null);
 
         String pkgName = pluginManager.getPluginsAPKName(libName);
@@ -2601,7 +2622,7 @@ final class WebViewCore {
             Log.w(LOGTAG, "Unable to resolve " + libName + " to a plugin APK");
             return null;
         }
-        
+
         try {
             return pluginManager.getPluginClass(pkgName, clsName);
         } catch (NameNotFoundException e) {
@@ -2656,7 +2677,7 @@ final class WebViewCore {
         view.mView = pluginView;
         return view;
     }
-    
+
     // called by JNI.  PluginWidget functions for creating an embedded View for
     // the surface drawing model.
     private ViewManager.ChildView addSurface(View pluginView, int x, int y,