ZoomControlEmbedded.java revision 90b6e4879304c6ac8240cdeb9a4aea94a27cda58 
1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16package android.webkit;
17
18import android.view.Gravity;
19import android.view.View;
20import android.view.ViewGroup;
21import android.widget.FrameLayout;
22import android.widget.Toast;
23import android.widget.ZoomButtonsController;
24
25class ZoomControlEmbedded implements ZoomControlBase {
26
27    private final ZoomManager mZoomManager;
28    private final WebView mWebView;
29
30    // The controller is lazily initialized in getControls() for performance.
31    private ZoomButtonsController mZoomButtonsController;
32
33    public ZoomControlEmbedded(ZoomManager zoomManager, WebView webView) {
34        mZoomManager = zoomManager;
35        mWebView = webView;
36    }
37
38    public void show() {
39        if (!getControls().isVisible()
40                && mZoomManager.mMinZoomScale < mZoomManager.mMaxZoomScale) {
41
42            mZoomButtonsController.setVisible(true);
43
44            WebSettings settings = mWebView.getSettings();
45            int count = settings.getDoubleTapToastCount();
46            if (mZoomManager.mInZoomOverview && count > 0) {
47                settings.setDoubleTapToastCount(--count);
48                Toast.makeText(mWebView.getContext(),
49                        com.android.internal.R.string.double_tap_toast,
50                        Toast.LENGTH_LONG).show();
51            }
52        }
53    }
54
55    public void hide() {
56        if (mZoomButtonsController != null) {
57            mZoomButtonsController.setVisible(false);
58        }
59    }
60
61    public boolean isVisible() {
62        return mZoomButtonsController != null && mZoomButtonsController.isVisible();
63    }
64
65    public void update() {
66        if (mZoomButtonsController == null) {
67            return;
68        }
69
70        boolean canZoomIn = mWebView.getScale() < mZoomManager.mMaxZoomScale;
71        boolean canZoomOut = mWebView.getScale() > mZoomManager.mMinZoomScale &&
72                                                  !mZoomManager.mInZoomOverview;
73        if (!canZoomIn && !canZoomOut) {
74            // Hide the zoom in and out buttons if the page cannot zoom
75            mZoomButtonsController.getZoomControls().setVisibility(View.GONE);
76        } else {
77            // Set each one individually, as a page may be able to zoom in or out
78            mZoomButtonsController.setZoomInEnabled(canZoomIn);
79            mZoomButtonsController.setZoomOutEnabled(canZoomOut);
80        }
81    }
82
83    private ZoomButtonsController getControls() {
84        if (mZoomButtonsController == null) {
85            mZoomButtonsController = new ZoomButtonsController(mWebView);
86            mZoomButtonsController.setOnZoomListener(new ZoomListener());
87            // ZoomButtonsController positions the buttons at the bottom, but in
88            // the middle. Change their layout parameters so they appear on the
89            // right.
90            View controls = mZoomButtonsController.getZoomControls();
91            ViewGroup.LayoutParams params = controls.getLayoutParams();
92            if (params instanceof FrameLayout.LayoutParams) {
93                ((FrameLayout.LayoutParams) params).gravity = Gravity.RIGHT;
94            }
95        }
96        return mZoomButtonsController;
97    }
98
99    private class ZoomListener implements ZoomButtonsController.OnZoomListener {
100
101        public void onVisibilityChanged(boolean visible) {
102            if (visible) {
103                mWebView.switchOutDrawHistory();
104                // Bring back the hidden zoom controls.
105                mZoomButtonsController.getZoomControls().setVisibility(View.VISIBLE);
106                update();
107            }
108        }
109
110        public void onZoom(boolean zoomIn) {
111            if (zoomIn) {
112                mWebView.zoomIn();
113            } else {
114                mWebView.zoomOut();
115            }
116            update();
117        }
118    }
119}
120