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;
<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>
@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);
}
}
}
/**
* 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();
}
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);
}