我正在使用EditText小部件,并希望修改用户长按视图时显示的上下文菜单.我遇到的问题是我需要知道长按文本中的字符位置,以便我可以确定我需要添加到上下文菜单中.基类是这样做的,因为菜单中的一个选项是“添加”word_clicked_on“To Dictionary”.在文本中设置ClickableSpans似乎不是一个解决方案,因为它消耗了点击事件,这使得无法在跨度内移动编辑光标.

解决方法:

这是我提出的解决方案,它确实有效,所以我想分享它：

首先我得出结论,我需要扩展EditText类,以便我可以拦截onTouchEvent,捕获ACTION_DOWN事件并保存位置.现在我有了下降点的位置,我可以调用getOffsetForPosition(downPointX,downPointY)并获取长按的字符位置.有一个大问题,直到SDK 14才添加getOffsetForPosition！为了使这个解决方案工作,我必须支持getOffsetForPosition和分支的功能,如果当前SDK早于SDK_INT 14.这是新类的源代码：

public class ScrapEditText extends EditText{

protected float LastDownPositionX, LastDownPositionY;

public ScrapEditText(Context context)

{

super(context);

}

public ScrapEditText(Context context, AttributeSet attrs)

{

super(context, attrs);

}

@Override

public boolean onTouchEvent(MotionEvent event)

{

final int action = event.getActionMasked();

if(action == MotionEvent.ACTION_DOWN)

{

LastDownPositionX = event.getX();

LastDownPositionY = event.getY();

}

return super.onTouchEvent(event);

}

public float GetLastDownPositionX()

{

return LastDownPositionX;

}

public float GetLastDownPositionY()

{

return LastDownPositionY;

}

public int GetOffsetForLastDownPosition()

{

if(Build.VERSION.SDK_INT > 13)

{

// as of SDK 14 the getOffsetForPosition was added to TextView

return getOffsetForPosition(LastDownPositionX, LastDownPositionY);

}

else

{

return GetOffsetForPositionOlderSdk();

}

}

public int GetOffsetForPositionOlderSdk()

{

if (getLayout() == null) return -1;

final int line = GetLineAtCoordinateOlderSDK(LastDownPositionY);

final int offset = GetOffsetAtCoordinateOlderSDK(line, LastDownPositionX);

return offset;

}

public int GetLineAtCoordinateOlderSDK(float y)

{

y -= getTotalPaddingTop();

// Clamp the position to inside of the view.

y = Math.max(0.0f, y);

y = Math.min(getHeight() - getTotalPaddingBottom() - 1, y);

y += getScrollY();

return getLayout().getLineForVertical((int) y);

}

protected int GetOffsetAtCoordinateOlderSDK(int line, float x) {

x = ConvertToLocalHorizontalCoordinateOlderSDK(x);

return getLayout().getOffsetForHorizontal(line, x);

}

protected float ConvertToLocalHorizontalCoordinateOlderSDK(float x) {

x -= getTotalPaddingLeft();

// Clamp the position to inside of the view.

x = Math.max(0.0f, x);

x = Math.min(getWidth() - getTotalPaddingRight() - 1, x);

x += getScrollX();

return x;

}

}

在您的Activity派生类中：

ScrapText = (ScrapEditText) findViewById(R.id.sample_text);

ScrapText.setOnCreateContextMenuListener(new View.OnCreateContextMenuListener(){

@Override

public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo)

{

int charOffset = FileText.GetOffsetForLastDownPosition();

}

});

标签：android

来源： https://codeday.me/bug/20190626/1292186.html