android - 修改 Android seekbar 小部件以垂直操作

Question

我正在尝试让一个垂直搜索栏与模拟器一起使用，但我有点卡住了。我可以让搜索栏以我想要的方式显示，我可以得到进展来做我想做的事，我可以修改onTouchEvent 让拇指垂直而不是水平。我不能做的是让拇指移到外面默认为 29 个水平像素，不使用 setThumbOffset()。这在本身不是问题。问题来自于我根本不理解 thumbOffset - 我猜。我想我可以(适本地)调整小部件，我很确定我做的不对。或者也许我可以如果我能弄清楚，只需使用 thumbOffset 。既然我可以正确计算进度我以为我只会使用线性小部件的进度函数 * (getTop() - getBottom()) 但那似乎没有这样做。但我无法弄清楚偏移量是多少以周围为中心。

顺便说一句，我真的不确定我在做什么onSizeChanged() 是理智的，或者如果它以后会咬我的屁股开。

这是 main.xml 布局:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >

    <com.mobilsemantic.mobipoll.SlideBar
        android:id="@+id/slide"
        android:layout_width="wrap_content"
        android:layout_height="fill_parent"
        android:max="100"
        android:progress="0"
        android:secondaryProgress="25" />

        <Button android:id="@+id/button"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:text="Hello, I am a Button" />

    <TextView android:id="@+id/tracking"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />

</LinearLayout>

还有类(忽略调试垃圾):

import android.content.Context;
import android.graphics.Canvas;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.widget.SeekBar;

public class SlideBar extends SeekBar {

        private int oHeight = 320, oWidth = 29;
        private int oProgress = -1, oOffset = -1;;
        private float xPos = -1, yPos = -1;
        private int top = -1, bottom = -1, left = -1, right = -1;

        public SlideBar(Context context) {
                super(context);
        }
        public SlideBar(Context context, AttributeSet attrs)
        {
                super(context, attrs);
                oOffset = this.getThumbOffset();
                oProgress = this.getProgress();
        }
        public SlideBar(Context context, AttributeSet attrs, int defStyle)
        {
                super(context, attrs, defStyle);
        }

        protected synchronized void onMeasure(int widthMeasureSpec, intheightMeasureSpec)
        {
                int height = View.MeasureSpec.getSize(heightMeasureSpec);
                oHeight = height;
                this.setMeasuredDimension(oWidth, oHeight);

        }
        protected void onSizeChanged(int w, int h, int oldw, int oldh)
        {
                super.onSizeChanged(h, w, oldw, oldh);
        }
        protected void onLayout(boolean changed, int l, int t, int r, int b)
        {
                super.onLayout(changed, l, t, r, b);
                left = l;
                right = r;
                top = t;
                bottom = b;
        }
        protected void onDraw(Canvas c)
        {
                c.rotate(90);
                c.translate(0,-29);
                super.onDraw(c);
        }
        public boolean onTouchEvent(MotionEvent event)
        {
                xPos = event.getX();
                yPos = event.getY();
                float progress = (yPos-this.getTop())/(this.getBottom()-this.getTop());
                oOffset = this.getThumbOffset();
                oProgress = this.getProgress();
                Log.d("offset" + System.nanoTime(), new Integer(oOffset).toString());
                Log.d("progress" + System.nanoTime(), new Integer(oProgress).toString());

                float offset;

                offset = progress * (this.getBottom()-this.getTop());

                this.setThumbOffset((int)offset);

                Log.d("offset_postsetprogress" + System.nanoTime(), new Integer(oOffset).toString());
                Log.d("progress_postsetprogress" + System.nanoTime(), new Integer(oProgress).toString());

                this.setProgress((int)(100*event.getY()/this.getBottom()));
                return true;
        }

}

Answer 1

我创建了一个可行的解决方案(至少对我来说，无论如何)，并创建了一个垂直的 SeekBar。 http://hackskrieg.wordpress.com/2012/04/20/working-vertical-seekbar-for-android/

此代码将正确选择/取消选择拇指、正确移动、正确更新监听器(仅在进度发生变化时!)、正确更新/绘制进度等。希望对您有所帮助。

public class VerticalSeekBar extends SeekBar {

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

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

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

protected void onSizeChanged(int w, int h, int oldw, int oldh) {
    super.onSizeChanged(h, w, oldh, oldw);
}

@Override
protected synchronized void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(heightMeasureSpec, widthMeasureSpec);
    setMeasuredDimension(getMeasuredHeight(), getMeasuredWidth());
}

protected void onDraw(Canvas c) {
    c.rotate(-90);
    c.translate(-getHeight(), 0);

    super.onDraw(c);
}

private OnSeekBarChangeListener onChangeListener;
@Override
public void setOnSeekBarChangeListener(OnSeekBarChangeListener onChangeListener){
    this.onChangeListener = onChangeListener;
}

private int lastProgress = 0;
@Override
public boolean onTouchEvent(MotionEvent event) {
    if (!isEnabled()) {
        return false;
    }

    switch (event.getAction()) {
    case MotionEvent.ACTION_DOWN:
        onChangeListener.onStartTrackingTouch(this);
        setPressed(true);
        setSelected(true);
        break;
    case MotionEvent.ACTION_MOVE:
        // Calling the super seems to help fix drawing problems
        super.onTouchEvent(event);
        int progress = getMax() - (int) (getMax() * event.getY() / getHeight());

        // Ensure progress stays within boundaries of the seekbar
        if(progress < 0) {progress = 0;}
        if(progress > getMax()) {progress = getMax();}

        // Draw progress
        setProgress(progress);

        // Only enact listener if the progress has actually changed
        // Otherwise the listener gets called ~5 times per change
        if(progress != lastProgress) {
            lastProgress = progress;
            onChangeListener.onProgressChanged(this, progress, true);
        }

        onSizeChanged(getWidth(), getHeight() , 0, 0);
        onChangeListener.onProgressChanged(this, getMax() - (int) (getMax() * event.getY() / getHeight()), true);
        setPressed(true);
        setSelected(true);
        break;
    case MotionEvent.ACTION_UP:
        onChangeListener.onStopTrackingTouch(this);
        setPressed(false);
        setSelected(false);
        break;
    case MotionEvent.ACTION_CANCEL:
        super.onTouchEvent(event);
        setPressed(false);
        setSelected(false);
        break;
    }
    return true;
}

public synchronized void setProgressAndThumb(int progress) {
    setProgress(getMax() - (getMax()- progress));
    onSizeChanged(getWidth(), getHeight() , 0, 0);
}

public synchronized void setMaximum(int maximum) {
    setMax(maximum);
}

public synchronized int getMaximum() {
    return getMax();
}
}

我刚刚将这个垂直的 SeekBar 放置在一个 LinearLayout 中，其中 layout_height 设置为 FILL_PARENT，layout_width 设置为 WRAP_CONTENT。

<LinearLayout
    android:layout_width="wrap_content"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <com.safetyculture.jsadroidtablet.VerticalSeekBar
        android:id="@+id/calculatorVerticalSeekBar"
        android:layout_width="wrap_content"
        android:layout_height="fill_parent"
        android:layout_gravity="bottom"
        android:max="4"
        android:progress="2" />

</LinearLayout>

注意:必须设置 OnSeekBarChangeListener，否则与 SeekBar 交互会产生 NullPointerException。