为webview添加复制文本的功能
需求描述:
- 长按WebView出现Context menu,显示"复制”菜单
- 点击上述菜单后选择文本，复制到剪贴板
- 用OnTouchListener实现长按实现(参照android.view.View)
- 实现WebView的Context menu(在Activity实例中实现)
- 实现复制文本功能(兼容多个sdk)
编码:
public class WebViewCopy {
private Activity activity;
private WebView webview;
private static boolean mIsSelectingText;
public static final String TAG=WebViewCopy.class.getSimpleName();
public WebViewCopy(final Activity activity, final WebView webView){
this.webview=webView;
this.activity=activity;
this.activity.registerForContextMenu(this.webview);
webView.requestFocus(View.FOCUS_DOWN);
webView.setOnTouchListener(new OnTouchListener() {
boolean mHasPerformedLongPress;
Runnable mPendingCheckForLongPress;
@Override
public boolean onTouch(final View v, MotionEvent event) {
/* webView.getSettings().setBuiltInZoomControls(false);
webView.getSettings().setSupportZoom(false);*/
Log.d(TAG, "event:" + event.getAction());
switch (event.getAction()) {
case MotionEvent.ACTION_UP:
mIsSelectingText = false;
if (!v.hasFocus()) {
v.requestFocus();
}
if (!mHasPerformedLongPress) {
// This is a tap, so remove the longpress check
if (mPendingCheckForLongPress != null) {
v.removeCallbacks(mPendingCheckForLongPress);
}
// v.performClick();
}
break;
case MotionEvent.ACTION_DOWN:
if (!v.hasFocus()) {
v.requestFocus();
}
if( mPendingCheckForLongPress == null) {
mPendingCheckForLongPress = new Runnable() {
public void run() {
//((WebView)v).performLongClick();
if(! mIsSelectingText) {
activity.openContextMenu(webview);
mHasPerformedLongPress = true;
mIsSelectingText = false;
}
}
};
}
mHasPerformedLongPress = false;
v. postDelayed(mPendingCheckForLongPress, ViewConfiguration.getLongPressTimeout());
break;
case MotionEvent.ACTION_MOVE:
final int x = (int) event.getX();
final int y = (int) event.getY();
// Be lenient about moving outside of buttons
int slop = ViewConfiguration.get(v.getContext()).getScaledTouchSlop();
if ((x < 0 - slop) || (x >= v.getWidth() + slop) ||
(y < 0 - slop) || (y >= v.getHeight() + slop)) {
if (mPendingCheckForLongPress != null) {
v. removeCallbacks(mPendingCheckForLongPress);
}
}
break;
default:
return false;
}
return false;
}
});
}
public static synchronized void emulateShiftHeld(WebView view)
{
try
{
KeyEvent shiftPressEvent = new KeyEvent(0, 0, KeyEvent.ACTION_DOWN,
KeyEvent.KEYCODE_SHIFT_LEFT, 0, 0);
shiftPressEvent.dispatch(view);
}
catch (Exception e)
{
Log.e(TAG, "Exception in emulateShiftHeld()", e);
}
}
public synchronized void onCreateContextMenu(ContextMenu menu, View v,
ContextMenuInfo menuInfo,final int copy,String menuString) {
MenuItem menuitem=menu.add(1, copy, Menu.NONE, menuString);
menuitem.setOnMenuItemClickListener(new OnMenuItemClickListener() {
@Override
public boolean onMenuItemClick(MenuItem item) {
if(item.getItemId()==copy){
//emulateShiftHeld(webview);
selectAndCopyText(webview);
}
return false;
}
});
}
public static synchronized void selectAndCopyText(WebView v) {
try {
mIsSelectingText = true;
//Method m = WebView.class.getMethod("emulateShiftHeld", Boolean.TYPE);
// m.invoke(v, false);
if (android.os.Build.VERSION.SDK_INT <= Build.VERSION_CODES.ECLAIR) {
Method m = WebView.class.getMethod("emulateShiftHeld", Boolean.TYPE);
m.invoke(v, false);
}
else {
Method m = WebView.class.getMethod("emulateShiftHeld");
m.invoke(v);
}
} catch (Exception e) {
// fallback
emulateShiftHeld(v);
}finally{
//Toast.makeText(activity, "Select text", Toast.LENGTH_SHORT).show();
}
}
}
public class WebViewCopy {
private Activity activity;
private WebView webview;
private static boolean mIsSelectingText;
public static final String TAG=WebViewCopy.class.getSimpleName();
public WebViewCopy(final Activity activity, final WebView webView){
this.webview=webView;
this.activity=activity;
this.activity.registerForContextMenu(this.webview);
webView.requestFocus(View.FOCUS_DOWN);
webView.setOnTouchListener(new OnTouchListener() {
boolean mHasPerformedLongPress;
Runnable mPendingCheckForLongPress;
@Override
public boolean onTouch(final View v, MotionEvent event) {
/* webView.getSettings().setBuiltInZoomControls(false);
webView.getSettings().setSupportZoom(false);*/
Log.d(TAG, "event:" + event.getAction());
switch (event.getAction()) {
case MotionEvent.ACTION_UP:
mIsSelectingText = false;
if (!v.hasFocus()) {
v.requestFocus();
}
if (!mHasPerformedLongPress) {
// This is a tap, so remove the longpress check
if (mPendingCheckForLongPress != null) {
v.removeCallbacks(mPendingCheckForLongPress);
}
// v.performClick();
}
break;
case MotionEvent.ACTION_DOWN:
if (!v.hasFocus()) {
v.requestFocus();
}
if( mPendingCheckForLongPress == null) {
mPendingCheckForLongPress = new Runnable() {
public void run() {
//((WebView)v).performLongClick();
if(! mIsSelectingText) {
activity.openContextMenu(webview);
mHasPerformedLongPress = true;
mIsSelectingText = false;
}
}
};
}
mHasPerformedLongPress = false;
v. postDelayed(mPendingCheckForLongPress, ViewConfiguration.getLongPressTimeout());
break;
case MotionEvent.ACTION_MOVE:
final int x = (int) event.getX();
final int y = (int) event.getY();
// Be lenient about moving outside of buttons
int slop = ViewConfiguration.get(v.getContext()).getScaledTouchSlop();
if ((x < 0 - slop) || (x >= v.getWidth() + slop) ||
(y < 0 - slop) || (y >= v.getHeight() + slop)) {
if (mPendingCheckForLongPress != null) {
v. removeCallbacks(mPendingCheckForLongPress);
}
}
break;
default:
return false;
}
return false;
}
});
}
public static synchronized void emulateShiftHeld(WebView view)
{
try
{
KeyEvent shiftPressEvent = new KeyEvent(0, 0, KeyEvent.ACTION_DOWN,
KeyEvent.KEYCODE_SHIFT_LEFT, 0, 0);
shiftPressEvent.dispatch(view);
}
catch (Exception e)
{
Log.e(TAG, "Exception in emulateShiftHeld()", e);
}
}
public synchronized void onCreateContextMenu(ContextMenu menu, View v,
ContextMenuInfo menuInfo,final int copy,String menuString) {
MenuItem menuitem=menu.add(1, copy, Menu.NONE, menuString);
menuitem.setOnMenuItemClickListener(new OnMenuItemClickListener() {
@Override
public boolean onMenuItemClick(MenuItem item) {
if(item.getItemId()==copy){
//emulateShiftHeld(webview);
selectAndCopyText(webview);
}
return false;
}
});
}
public static synchronized void selectAndCopyText(WebView v) {
try {
mIsSelectingText = true;
//Method m = WebView.class.getMethod("emulateShiftHeld", Boolean.TYPE);
// m.invoke(v, false);
if (android.os.Build.VERSION.SDK_INT <= Build.VERSION_CODES.ECLAIR) {
Method m = WebView.class.getMethod("emulateShiftHeld", Boolean.TYPE);
m.invoke(v, false);
}
else {
Method m = WebView.class.getMethod("emulateShiftHeld");
m.invoke(v);
}
} catch (Exception e) {
// fallback
emulateShiftHeld(v);
}finally{
//Toast.makeText(activity, "Select text", Toast.LENGTH_SHORT).show();
}
}
}
下面的代码在activity中写:
1) 在onCreate中生成 WebViewCopy 实例: copy = new WebViewCopy(this, _webView);
2) 在onCreateContextMenu中注入复制菜单public void onCreateContextMenu(ContextMenu menu, View v,
- ContextMenuInfo menuInfo) {
- copy.onCreateContextMenu(menu, v, menuInfo,COPY,getString(R.string.copy));
- super.onCreateContextMenu(menu, v, menuInfo);
ContextMenuInfo menuInfo) {
copy.onCreateContextMenu(menu, v, menuInfo,COPY,getString(R.string.copy));
super.onCreateContextMenu(menu, v, menuInfo);
}
回顾与总结:
OnTouchListener可能在一些时候更本不响应，如Zoom Button出现后。这得让WebView重新获取焦点，
这是WebView又一已知的Bug. 整个难点在于重新获取焦点: webview.requestFocus();
参考： http://code.google.com/p/android/issues/detail?id=7189