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

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