src/android_webview/java/src/org/chromium/android_webview/AwZoomControls.java

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 package org.chromium.android_webview;
   6
   7 import android.view.Gravity;
   8 import android.view.View;
   9 import android.view.ViewGroup;
  10 import android.widget.FrameLayout;
  11 import android.widget.ZoomButtonsController;
  12
  13 import org.chromium.content.browser.ContentViewCore.ZoomControlsDelegate;
  14
  15 class AwZoomControls implements ZoomControlsDelegate {
  16
  17     private AwContents mAwContents;
  18     // It is advised to use getZoomController() where possible.
  19     private ZoomButtonsController mZoomButtonsController;
  20
  21     AwZoomControls(AwContents awContents) {
  22         mAwContents = awContents;
  23     }
  24
  25     @Override
  26     public void invokeZoomPicker() {
  27         ZoomButtonsController zoomController = getZoomController();
  28         if (zoomController != null) {
  29             zoomController.setVisible(true);
  30         }
  31     }
  32
  33     @Override
  34     public void dismissZoomPicker() {
  35         ZoomButtonsController zoomController = getZoomController();
  36         if (zoomController != null) {
  37             zoomController.setVisible(false);
  38         }
  39     }
  40
  41     @Override
  42     public void updateZoomControls() {
  43         ZoomButtonsController zoomController = getZoomController();
  44         if (zoomController == null) {
  45             return;
  46         }
  47         boolean canZoomIn = mAwContents.canZoomIn();
  48         boolean canZoomOut = mAwContents.canZoomOut();
  49         if (!canZoomIn && !canZoomOut) {
  50             // Hide the zoom in and out buttons if the page cannot zoom
  51             zoomController.getZoomControls().setVisibility(View.GONE);
  52         } else {
  53             // Set each one individually, as a page may be able to zoom in or out
  54             zoomController.setZoomInEnabled(canZoomIn);
  55             zoomController.setZoomOutEnabled(canZoomOut);
  56         }
  57     }
  58
  59     // This method is used in tests. It doesn't modify the state of zoom controls.
  60     View getZoomControlsViewForTest() {
  61         return mZoomButtonsController != null ? mZoomButtonsController.getZoomControls() : null;
  62     }
  63
  64     private ZoomButtonsController getZoomController() {
  65         if (mZoomButtonsController == null
  66                 && mAwContents.getSettings().shouldDisplayZoomControls()) {
  67             mZoomButtonsController = new ZoomButtonsController(
  68                     mAwContents.getContentViewCore().getContainerView());
  69             mZoomButtonsController.setOnZoomListener(new ZoomListener());
  70             // ZoomButtonsController positions the buttons at the bottom, but in
  71             // the middle. Change their layout parameters so they appear on the
  72             // right.
  73             View controls = mZoomButtonsController.getZoomControls();
  74             ViewGroup.LayoutParams params = controls.getLayoutParams();
  75             if (params instanceof FrameLayout.LayoutParams) {
  76                 ((FrameLayout.LayoutParams) params).gravity = Gravity.RIGHT;
  77             }
  78         }
  79         return mZoomButtonsController;
  80     }
  81
  82     private class ZoomListener implements ZoomButtonsController.OnZoomListener {
  83         @Override
  84         public void onVisibilityChanged(boolean visible) {
  85             if (visible) {
  86                 // Bring back the hidden zoom controls.
  87                 mZoomButtonsController.getZoomControls().setVisibility(View.VISIBLE);
  88                 updateZoomControls();
  89             }
  90         }
  91
  92         @Override
  93         public void onZoom(boolean zoomIn) {
  94             if (zoomIn) {
  95                 mAwContents.zoomIn();
  96             } else {
  97                 mAwContents.zoomOut();
  98             }
  99             // ContentView will call updateZoomControls after its current page scale
 100             // is got updated from the native code.
 101         }
 102     }
 103 }