Android Browser学习五 多窗口: Tab 整体结构

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2014/02/09 13:02
阅读数 4.5K

前面说了这么多却发现我们的Tab还没有介绍, Tab到底是个什么东西呢?

其实是一个含有两个WebView 成员一个WebViewController成员的类: 其中PageState用来真正存储这个tab网页的一些信息,包括url 标题 图标等

// Main WebView wrapper tab的容器
    private View mContainer;
    // Main WebView 显示网页的webview
    private WebView mMainView; 
    // Subwindow container 
    private View mSubViewContainer;
    // Subwindow WebView在一个tab可能会弹出 另一个WebView的dialog  使用subwebview实现 (True if the new        window should be a dialog, rather than a full-size window.)
    private WebView mSubView;



其中mContainer就是tab的主Ui 了 他一般是一个形如"


<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:fitsSystemWindows="true"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <!-- Wrapper layout for the WebView, which must be in a FrameLayout. -->
    <FrameLayout android:id="@+id/webview_wrapper"
        android:layout_width="match_parent"
        android:layout_height="0dip"
        android:layout_weight="1" />

    <!-- Geolocation permissions prompt -->
    <ViewStub android:id="@+id/geolocation_permissions_prompt"
        android:layout="@layout/geolocation_permissions_prompt"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

</LinearLayout>



这样的布局, 通过 BaseUI的onSetWebView设置:



@Override
    public void onSetWebView(Tab tab, WebView webView) {
        View container = tab.getViewContainer();
        if (container == null) {
            // The tab consists of a container view, which contains the main
            // WebView, as well as any other UI elements associated with the tab.
            container = mActivity.getLayoutInflat().inflate(R.layout.tab,
                    mContentView, false);//把tab的ContainerView  Attach到Activity
            tab.setViewContainer(container);
        }
        if (tab.getWebView() != webView) { //如果tab当前的 mMainWebview 和 以前的webview不一样就把以前的那个webview 从 Container 移除掉
            // Just remove the old one.
            FrameLayout wrapper =
                    (FrameLayout) container.findViewById(R.id.webview_wrapper);
            wrapper.removeView(tab.getWebView());
        }
    }




这个函数是谁调用的呢? 终归肯定是Controller进行的, 但是这里设计就有点乱了:

顺序是这样:  Controller::setActiveTab -> TabControl::setCurrentTab -> Tab::setWebView -> Controler ::onSetWebView  -> BaseUI::onSetWebView 



 Controller调用 BaseUI 的setActiveTab函数 (其实最后是attachTabToContentView)把Tab的mWebView和container 关联起来:

protected void attachTabToContentView(Tab tab) {
        if ((tab == null) || (tab.getWebView() == null)) {
            return;
        }
        View container = tab.getViewContainer(); //对应tab的layout
        WebView mainView  = tab.getWebView();
        // Attach the WebView to the container and then attach the
        // container to the content view.
        //把Tab的container添加到mContentView
        FrameLayout wrapper =
                (FrameLayout) container.findViewById(R.id.webview_wrapper);
        ViewGroup parent = (ViewGroup) mainView.getParent();
        if (parent != wrapper) {
            if (parent != null) {
                Log.w(LOGTAG, "mMainView already has a parent in"
                        + " attachTabToContentView!");
                parent.removeView(mainView);
            }
            wrapper.addView(mainView);
        } else {
            Log.w(LOGTAG, "mMainView is already attached to wrapper in"
                    + " attachTabToContentView!");
        }
        parent = (ViewGroup) container.getParent();
        if (parent != mContentView) {
            if (parent != null) {
                Log.w(LOGTAG, "mContainer already has a parent in"
                        + " attachTabToContentView!");
                parent.removeView(container);
            }
            mContentView.addView(container, COVER_SCREEN_PARAMS);
        } else {
            Log.w(LOGTAG, "mContainer is already attached to content in"
                    + " attachTabToContentView!");
        }
        mUiController.attachSubWindow(tab);
    }

这样我们就明白了, Activity只是一个容器, 当哪个Tab放到前台, BaseUI就拿到对应Tab的Container和Webview , 把这两个空间attach到Activity的ContentView中去

之所以这样做, 可能是因为作者想让  BaseUI来进行把View attach到Activity上的操作 , Tab只做控制Webview load网页的操作; 他们之间的交互由Controller来控制.但是感觉这个设计可能有些乱了.


Tab获取当前快照的函数:

protected void capture() {
        if (mMainView == null || mCapture == null) return;
        if (mMainView.getContentWidth() <= 0 || mMainView.getContentHeight() <= 0) {
            return;
        }
        Canvas c = new Canvas(mCapture);
        final int left = mMainView.getScrollX(); //快照抓取的是tab的顶部
        final int top = mMainView.getScrollY() + mMainView.getVisibleTitleHeight();
        int state = c.save();
        c.translate(-left, -top);
        float scale = mCaptureWidth / (float) mMainView.getWidth();
        c.scale(scale, scale, left, top);
        if (mMainView instanceof BrowserWebView) {
            ((BrowserWebView)mMainView).drawContent(c);
        } else {
            mMainView.draw(c);
        }
        c.restoreToCount(state);
        // manually anti-alias the edges for the tilt
        c.drawRect(0, 0, 1, mCapture.getHeight(), sAlphaPaint);
        c.drawRect(mCapture.getWidth() - 1, 0, mCapture.getWidth(),
                mCapture.getHeight(), sAlphaPaint);
        c.drawRect(0, 0, mCapture.getWidth(), 1, sAlphaPaint);
        c.drawRect(0, mCapture.getHeight() - 1, mCapture.getWidth(),
                mCapture.getHeight(), sAlphaPaint);
        c.setBitmap(null);//释放canvas绘制的bitmap
        mHandler.removeMessages(MSG_CAPTURE);
        persistThumbnail();
        TabControl tc = mWebViewController.getTabControl();
        if (tc != null) {
            OnThumbnailUpdatedListener updateListener
                    = tc.getOnThumbnailUpdatedListener();
            if (updateListener != null) {//通知更新了缩略图
                updateListener.onThumbnailUpdated(this);
            }
        }
    }



Tab 保存 当前网页的函数


/**
     * 保存离线阅读的一些数据
     * @return
     */
    public ContentValues createSnapshotValues() {
        if (mMainView == null) return null;
        SnapshotByteArrayOutputStream bos = new SnapshotByteArrayOutputStream();
        try {
            GZIPOutputStream stream = new GZIPOutputStream(bos);
            if (!mMainView.saveViewState(stream)) {
                return null;
            }
            stream.flush();
            stream.close();
        } catch (Exception e) {
            Log.w(LOGTAG, "Failed to save view state", e);
            return null;
        }
        byte[] data = bos.toByteArray();
        ContentValues values = new ContentValues();
        values.put(Snapshots.TITLE, mCurrentState.mTitle);//标题
        values.put(Snapshots.URL, mCurrentState.mUrl);//url
        values.put(Snapshots.VIEWSTATE, data);
        values.put(Snapshots.BACKGROUND, mMainView.getPageBackgroundColor());//背景
        values.put(Snapshots.DATE_CREATED, System.currentTimeMillis());//时间
        values.put(Snapshots.FAVICON, compressBitmap(getFavicon()));//网址图标
        Bitmap screenshot = Controller.createScreenshot(mMainView,
                Controller.getDesiredThumbnailWidth(mContext),
                Controller.getDesiredThumbnailHeight(mContext));
        values.put(Snapshots.THUMBNAIL, compressBitmap(screenshot));
        return values;
    }

    public byte[] compressBitmap(Bitmap bitmap) {
        if (bitmap == null) {
            return null;
        }
        ByteArrayOutputStream stream = new ByteArrayOutputStream();
        bitmap.compress(CompressFormat.PNG, 100, stream);
        return stream.toByteArray();
    }



处理SSLError的函数


private void handleProceededAfterSslError(SslError error) {
        if (error.getUrl().equals(mCurrentState.mUrl)) {
            // The security state should currently be SECURITY_STATE_SECURE.
            setSecurityState(SecurityState.SECURITY_STATE_BAD_CERTIFICATE);
            mCurrentState.mSslCertificateError = error;
        } else if (getSecurityState() == SecurityState.SECURITY_STATE_SECURE) {
            // The page's main resource is secure and this error is for a
            // sub-resource.
            setSecurityState(SecurityState.SECURITY_STATE_MIXED);
        }
    }



/**
         * Called when an SSL error occurred while loading a resource, but the
         * WebView but chose to proceed anyway based on a decision retained
         * from a previous response to onReceivedSslError(). We update our
         * security state to reflect this.
         */
        @Override
        public void onProceededAfterSslError(WebView view, SslError error) {
            handleProceededAfterSslError(error);
        }





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http://www.opench.cn/html/108.html 帮我看一下这个是不是有错误呢???
2014/02/10 01:51
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2014/02/10 01:51
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