gecko/mobile/android/base/gfx/PlaceholderLayerClient.java

/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
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 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
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 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
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 * The Original Code is Mozilla Android code.
 *
 * The Initial Developer of the Original Code is Mozilla Foundation.
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 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Patrick Walton <pcwalton@mozilla.com>
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 * either the GNU General Public License Version 2 or later (the "GPL"), or
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package org.mozilla.gecko.gfx;

import org.mozilla.gecko.GeckoApp;
import org.mozilla.gecko.GeckoAppShell;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.util.Log;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.ByteArrayInputStream;
import java.nio.ByteBuffer;

/**
 * A stand-in for Gecko that renders cached content of the previous page. We use this until Gecko
 * is up, then we hand off control to it.
 */
public class PlaceholderLayerClient {
    private static final String LOGTAG = "PlaceholderLayerClient";

    private final LayerController mLayerController;

    private ViewportMetrics mViewport;
    private boolean mViewportUnknown;
    private int mWidth, mHeight, mFormat;
    private ByteBuffer mBuffer;

    public PlaceholderLayerClient(LayerController controller, String lastViewport) {
        mLayerController = controller;

        mViewportUnknown = true;
        if (lastViewport != null) {
            try {
                JSONObject viewportObject = new JSONObject(lastViewport);
                mViewport = new ViewportMetrics(viewportObject);
                mViewportUnknown = false;
            } catch (JSONException e) {
                Log.e(LOGTAG, "Error parsing saved viewport!");
                mViewport = new ViewportMetrics();
            }
        } else {
            mViewport = new ViewportMetrics();
        }
        loadScreenshot();


        if (mViewportUnknown)
            mViewport.setViewport(mLayerController.getViewport());
        mLayerController.setViewportMetrics(mViewport);

        BufferedCairoImage image = new BufferedCairoImage(mBuffer, mWidth, mHeight, mFormat);
        SingleTileLayer tileLayer = new SingleTileLayer(image);

        tileLayer.beginTransaction();
        try {
            tileLayer.setOrigin(PointUtils.round(mViewport.getDisplayportOrigin()));
        } finally {
            tileLayer.endTransaction();
        }

        mLayerController.setRoot(tileLayer);
    }

    public void destroy() {
        if (mBuffer != null) {
            GeckoAppShell.freeDirectBuffer(mBuffer);
            mBuffer = null;
        }
    }

    boolean loadScreenshot() {
        if (GeckoApp.mAppContext.mLastScreen == null)
            return false;

        Bitmap bitmap = BitmapFactory.decodeStream(new ByteArrayInputStream(GeckoApp.mAppContext.mLastScreen));
        if (bitmap == null)
            return false;

        Bitmap.Config config = bitmap.getConfig();

        mWidth = bitmap.getWidth();
        mHeight = bitmap.getHeight();
        mFormat = CairoUtils.bitmapConfigToCairoFormat(config);

        int bpp = CairoUtils.bitsPerPixelForCairoFormat(mFormat) / 8;
        mBuffer = GeckoAppShell.allocateDirectBuffer(mWidth * mHeight * bpp);

        bitmap.copyPixelsToBuffer(mBuffer.asIntBuffer());

        if (mViewportUnknown) {
            mViewport.setPageSize(new FloatSize(mWidth, mHeight));
            mLayerController.setPageSize(mViewport.getPageSize());
        }

        return true;
    }
}