Android seekbar解决方案

Question

是否可以让搜索栏仅在拇指移动时移动。现在搜索栏甚至在手指触摸时移动progressdrawable。我们如何禁用搜索栏的移动progressdrawable 的手指触摸？

谢谢。

Answer 1

我发现 Ravi's solution 的问题是不是很感人和移动到当前拇指位置之外仍会导致跳跃。

下面的类解决了这个问题，并用一个小的增量替换了触摸跳转，就像使用箭头键一样。

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import android.content.Context;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.view.KeyEvent;
import android.view.MotionEvent;
import android.widget.SeekBar;

/**
 * A NoSkipSeekBar is an extension of {@link SeekBar} that prevents jumps in position
 * by touching outside the current thumb position. Such touches are replaced by
 * an increment or decrement the same as would be achieved using a DPAD's Left or
 * Right arrow keys.
 */
public class NoSkipSeekBar extends SeekBar {

    public NoSkipSeekBar(Context context) {
        super(context);
    }

    public NoSkipSeekBar(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public NoSkipSeekBar(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    private boolean isDragging;

    private boolean isWithinThumb(MotionEvent event) {
        return getThumb().getBounds().contains((int)event.getX(), (int)event.getY());
    }

    private void increment(int direction) {
        if (direction != 0) {
            final KeyEvent key = new KeyEvent(KeyEvent.ACTION_DOWN, 
                    direction < 0 ? KeyEvent.KEYCODE_DPAD_LEFT : KeyEvent.KEYCODE_DPAD_RIGHT);
            onKeyDown(key.getKeyCode(), key);
        }
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        if (!isEnabled() || getThumb() == null) return super.onTouchEvent(event);

        switch (event.getAction()) {
        case MotionEvent.ACTION_DOWN:
            if (isWithinThumb(event)) {
                isDragging = true;
                return super.onTouchEvent(event);
            } else {
                return true;
            }

        case MotionEvent.ACTION_UP:
            isDragging = false;
            if (isWithinThumb(event)) {
                return super.onTouchEvent(event);
            } else {
                final Rect r = getThumb().getBounds();
                increment((int)event.getX() - (r.left + r.right) / 2);
                return true;
            }

        case MotionEvent.ACTION_MOVE:
            if (!isDragging) return true;
            break;

        case MotionEvent.ACTION_CANCEL:
            isDragging = false;
            break;
        }

        return super.onTouchEvent(event);
    }
}