自定义seekbar上的Android标签

自定义seekbar上的Android标签,android,android-layout,Android,Android Layout,我有SeekBar的自定义样式,我想添加标签。SeekBar具有可绘制的进度,如下所示: <?xml version="1.0" encoding="utf-8"?> <layer-list xmlns:android="http://schemas.android.com/apk/res/android" > <item android:id="@android:id/background" android:drawable

我有
SeekBar
的自定义样式,我想添加标签。
SeekBar
具有可绘制的进度,如下所示:

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >
    <item
        android:id="@android:id/background"
        android:drawable="@drawable/seekbar_background"/>
</layer-list>

seekbar\u背景
9-patch如下所示:

我想在酒吧的每一端都贴上标签。最好,标签上的文字位于灯泡两侧的中心。似乎我应该能够将
TextView
居中放置在
SeekBar
的端点上,但我找不到将一个视图的中心与另一个视图的边缘对齐的方法


有没有一种方法,或者使用
SeekBar
API,或者通过巧妙地使用布局对齐来实现这一点?

我认为创建自定义视图/视图组可以实现这一点,下面是一些我认为可以实现的示例

main.xml:

<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:custom="http://schemas.android.com/apk/res/com.example.TestApp"
    android:layout_height="match_parent"
    android:layout_width="match_parent"
    android:id="@+id/root">

    <com.example.TestApp.LabelledSeekBar
        android:layout_width="300dp"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        custom:labelLeft="@string/left_label"
        custom:labelRight="@string/right_label"
        custom:labelPaddingBottom="@dimen/label_padding_bottom"
        custom:labelCenterSidePadding="@dimen/label_padding_side"
        android:textSize="@dimen/label_text_size"
        android:textColor="@android:color/white"
        android:textStyle="italic"
        android:progressDrawable="@drawable/seek_progress" />

</RelativeLayout>

具有自定义属性的attrs.xml:

<resources>
    <declare-styleable name="LabelledSeekBar">
        <attr name="labelLeft" format="string"/>
        <attr name="labelRight" format="string"/>
        <attr name="labelPaddingBottom" format="dimension"/>
        <!-- This is bulb center padding -->
        <attr name="labelCenterSidePadding" format="dimension"/>
    </declare-styleable>
</resources>

自定义视图/视图组的核心思想就是提供适当的文本放置,并对视图进行正确的测量。自定义视图组本身是(下面有很多代码):

公共类LabelledSeekBar扩展了视图组{
/**SeekBar本身*/
私人最终SeekBar mSeekBar;
/**左端标签*/
私有字符串mleftlab=null;
/**右端标签*/
私有字符串mRightLabel=null;
/**标签的底部衬垫*/
私有静态final int DEFAULT\u LABEL\u PADDING\u BOTTOM=10;//px
private int mLabelPaddingBottom=默认值\u LABEL\u PADDING\u BOTTOM;
/**“灯泡”的中心,用于在中心上方绘制标签*/
私有静态final int DEFAULT\u LABEL\u PADDING\u SIDE=10;//px
private int mLabelCenterPadding=默认的\u标签\u填充\u侧;
/**这里是标签属性,它们类似于文本视图*/
私有静态final int DEFAULT_TEXT_SIZE=10;//px
私有静态final int DEFAULT\u TEXT\u COLOR=COLOR.BLACK;//px
私有静态最终字体默认值\u TEXT\u STYLE=Typeface.DEFAULT;//px
private int mTextSize=默认文本大小;
private int mTextColor=默认的文本颜色;
私有字体mTextStyle=默认的文本样式;
/**标签和矩形的边界*/
private Rect mLeftTextBound=null;
private Rect mrighttextbund=null;
/**SeekBar的矩形*/
private Rect mSeekBarRect=null;
/**SeekBar的默认高度*/
private int mDefaultSeekBarHeight=0;
/**为文本绘制*/
私有绘制mTextPaint=null;
/**标记是否绘制标签*/
私有布尔值mDrawLabels=false;
/**
*建造师
*/
公共标签seekbar(最终上下文){
超级(上下文);
mSeekBar=新SeekBar(上下文);
初始化(空);
}
/**
*建造师
*/
公共标签seekbar(最终上下文,最终属性集属性){
超级(上下文,attrs);
mSeekBar=新SeekBar(上下文,属性);
init(attrs);
}
/**
*建造师
*/
公共标签seekbar(最终上下文、最终属性集属性、最终int-defStyle){
超级(上下文、属性、定义样式);
mSeekBar=新SeekBar(上下文、属性、定义样式);
init(attrs);
}
@凌驾
仅限受保护的无效布局(最终布尔值已更改、最终整数l、最终整数t、最终整数r、最终整数b){
mseekbarct.layout(mSeekBarRect.left、mSeekBarRect.top、mSeekBarRect.right、mSeekBarRect.bottom);
}
/**
*从xml初始化搜索栏扩展属性
*
*@param attributeSet{@link attributeSet}
*/
私有void init(最终属性集属性集){
最终类型Darray attrsArray=getContext()。获取StyledAttributes(attributeSet,R.styleable.LabelledSeekBar,0,0);
mDefaultSeekBarHeight=getResources().getDimensionPixelSize(R.dimen.default\u seekbar\u height);
mleftlab=attrsArray.getString(R.styleable.LabelledSeekBar_labelLeft);
mRightLabel=attrsArray.getString(R.styleable.LabelledSeekBar\u labelRight);
mLabelPaddingBottom=attrsArray.getDimensionPixelOffset(R.styleable.LabelledSeekBar\u labelPaddingBottom,默认的\u LABEL\u PADDING\u BOTTOM);
mLabelCenterPadding=attrsArray.getDimensionPixelOffset(R.styleable.LabelledSeekBar\u labelCenterSidePadding,默认值\u LABEL\u PADDING\u SIDE);
//现在获取所需的文本属性
final int textSizeResource=attributeSet.getAttributeResourceValue(“http://schemas.android.com/apk/res/android“,”文本大小“,0);
如果(0!=textSizeResource){
mTextSize=getResources().getDimensionPixelSize(textSizeResource);
}
final int textColorResource=attributeSet.getAttributeResourceValue(“http://schemas.android.com/apk/res/android“,”文本颜色“,0);
如果(0!=textColorResource){
mTextColor=getResources().getColor(textColorResource);
}
final int typeface=attributeSet.getAttributeIntValue(“http://schemas.android.com/apk/res/android“,”文本样式“,0);
开关(字体){
//正常的
案例0:
mTextStyle=Typeface.create(Typeface.DEFAULT,Typeface.NORMAL);
打破
//大胆的
案例1:
mTextStyle=Typeface.create(Typeface.DEFAULT,Typeface.BOLD);
打破
//斜体
案例2:
mTextStyle=Typeface.create(Typeface.DEFAULT,Typeface.ITALIC);
打破
//粗体|斜体
案例3:
mTextStyle=Typeface.create(Typeface.DEFAULT,Typeface.BOLD\U ITALIC);
打破
}
mTextPaint=新的TextPaint();
mTextPaint.setColor(mTextColor);
mTextPaint.setTextSize(mTextSize);
mTextPaint.setTypeface(mTextStyle);
mTextPaint.setTextAlign(Paint.Align.LEFT);
mTextPaint.setStyle(Paint.Style.FILL);
阿迪维
public class LabelledSeekBar extends ViewGroup {

    /** SeekBar itself */
    private final SeekBar mSeekBar;
    /** Label for left end */
    private String mLeftLabel = null;
    /** Label for right end */
    private String mRightLabel = null;
    /** Bottom paddings for labels */
    private static final int DEFAULT_LABEL_PADDING_BOTTOM = 10; // px
    private int mLabelPaddingBottom = DEFAULT_LABEL_PADDING_BOTTOM;
    /** Center of 'bulbs' to draw labels above centered */
    private static final int DEFAULT_LABEL_PADDING_SIDE = 10; // px
    private int mLabelCenterPadding = DEFAULT_LABEL_PADDING_SIDE;
    /** Here goes labels attributes, they are similar to TextViews ones */
    private static final int DEFAULT_TEXT_SIZE = 10; // px
    private static final int DEFAULT_TEXT_COLOR = Color.BLACK; // px
    private static final Typeface DEFAULT_TEXT_STYLE = Typeface.DEFAULT; // px
    private int mTextSize = DEFAULT_TEXT_SIZE;
    private int mTextColor = DEFAULT_TEXT_COLOR;
    private Typeface mTextStyle = DEFAULT_TEXT_STYLE;
    /** Bounds for labels rects */
    private Rect mLeftTextBound = null;
    private Rect mRightTextBound = null;
    /** Rect for SeekBar */
    private Rect mSeekBarRect = null;
    /** Default height for SeekBar */
    private int mDefaultSeekBarHeight = 0;
    /** Paint for text */
    private Paint mTextPaint = null;
    /** Flag to draw or not the labels */
    private boolean mDrawLabels = false;

    /**
     * Constructor
     */
    public LabelledSeekBar(final Context context) {
        super(context);
        mSeekBar = new SeekBar(context);
        init(null);
    }

    /**
     * Constructor
     */
    public LabelledSeekBar(final Context context, final AttributeSet attrs) {
        super(context, attrs);
        mSeekBar = new SeekBar(context, attrs);
        init(attrs);
    }

    /**
     * Constructor
     */
    public LabelledSeekBar(final Context context, final AttributeSet attrs, final int defStyle) {
        super(context, attrs, defStyle);
        mSeekBar = new SeekBar(context, attrs, defStyle);
        init(attrs);
    }

    @Override
    protected void onLayout(final boolean changed, final int l, final int t, final int r, final int b) {
        mSeekBar.layout(mSeekBarRect.left, mSeekBarRect.top, mSeekBarRect.right, mSeekBarRect.bottom);
    }

    /**
     * Initializes Seek bar extended attributes from xml
     *
     * @param attributeSet {@link AttributeSet}
     */
    private void init(final AttributeSet attributeSet) {
        final TypedArray attrsArray = getContext().obtainStyledAttributes(attributeSet, R.styleable.LabelledSeekBar, 0, 0);

        mDefaultSeekBarHeight = getResources().getDimensionPixelSize(R.dimen.default_seekbar_height);

        mLeftLabel = attrsArray.getString(R.styleable.LabelledSeekBar_labelLeft);
        mRightLabel = attrsArray.getString(R.styleable.LabelledSeekBar_labelRight);
        mLabelPaddingBottom = attrsArray.getDimensionPixelOffset(R.styleable.LabelledSeekBar_labelPaddingBottom, DEFAULT_LABEL_PADDING_BOTTOM);
        mLabelCenterPadding = attrsArray.getDimensionPixelOffset(R.styleable.LabelledSeekBar_labelCenterSidePadding, DEFAULT_LABEL_PADDING_SIDE);

        // Now get needed Text attributes
        final int textSizeResource = attributeSet.getAttributeResourceValue("http://schemas.android.com/apk/res/android", "textSize", 0);

        if (0 != textSizeResource) {
            mTextSize = getResources().getDimensionPixelSize(textSizeResource);
        }

        final int textColorResource = attributeSet.getAttributeResourceValue("http://schemas.android.com/apk/res/android", "textColor", 0);

        if (0 != textColorResource) {
            mTextColor = getResources().getColor(textColorResource);
        }

        final int typeface = attributeSet.getAttributeIntValue("http://schemas.android.com/apk/res/android", "textStyle", 0);

        switch (typeface) {
            // normale
            case 0:
                mTextStyle = Typeface.create(Typeface.DEFAULT, Typeface.NORMAL);
                break;
            // bold
            case 1:
                mTextStyle = Typeface.create(Typeface.DEFAULT, Typeface.BOLD);
                break;
            // italic
            case 2:
                mTextStyle = Typeface.create(Typeface.DEFAULT, Typeface.ITALIC);
                break;
            // bold | italic
            case 3:
                mTextStyle = Typeface.create(Typeface.DEFAULT, Typeface.BOLD_ITALIC);
                break;
        }

        mTextPaint = new TextPaint();
        mTextPaint.setColor(mTextColor);
        mTextPaint.setTextSize(mTextSize);
        mTextPaint.setTypeface(mTextStyle);
        mTextPaint.setTextAlign(Paint.Align.LEFT);
        mTextPaint.setStyle(Paint.Style.FILL);

        addView(mSeekBar);
    }

    /**
     * Setters for labels
     *
     * @param leftLabel {@link String}
     * @param rightLabel {@link String}
     */
    public void setLabels(final String leftLabel, final String rightLabel) {
        mLeftLabel = leftLabel;
        mRightLabel = rightLabel;

        requestLayout();
    }

    @Override
    protected synchronized void onMeasure(final int widthMeasureSpec, final int heightMeasureSpec) {
        // measure labels height - this logic is not very strict and can be changed
        mLeftTextBound = new Rect();
        mTextPaint.getTextBounds(mLeftLabel, 0, mLeftLabel.length(), mLeftTextBound);
        mRightTextBound = new Rect();
        mTextPaint.getTextBounds(mRightLabel, 0, mRightLabel.length(), mRightTextBound);

        final int labelHeight = Math.max(mLeftTextBound.height(), mRightTextBound.height());
        final int desiredMinHeight = labelHeight + mLabelPaddingBottom;
        final int desiredMinWidth = mLeftTextBound.width() + mRightTextBound.width();
        final int widthSize = MeasureSpec.getSize(widthMeasureSpec);
        final int widthMode = MeasureSpec.getMode(widthMeasureSpec);
        final int heightSize = MeasureSpec.getSize(heightMeasureSpec);
        final int heightMode = MeasureSpec.getMode(heightMeasureSpec);
        int measuredWidth = 0;
        int measuredHeight = 0;

        mSeekBarRect = new Rect();

        // Calculate width
        switch (widthMode) {
            case MeasureSpec.EXACTLY:
            case MeasureSpec.AT_MOST:
                if (widthSize < desiredMinWidth) {
                    mDrawLabels = false;
                } else {
                    mDrawLabels = true;
                    mSeekBarRect.set(mLeftTextBound.width() / 2 - mLabelCenterPadding, desiredMinHeight,
                            widthSize - mRightTextBound.width() / 2 + mLabelCenterPadding, heightSize);
                }
                measuredWidth = widthSize;
                break;

            case MeasureSpec.UNSPECIFIED:
                mDrawLabels = true;
                measuredWidth = desiredMinWidth + mLabelCenterPadding * 4;
                mSeekBarRect.set(mLeftTextBound.width() / 2 - mLabelCenterPadding, desiredMinHeight,
                        widthSize - mRightTextBound.width() / 2 + mLabelCenterPadding, heightSize);
                break;
        }

        if (mDrawLabels) {
            // Calculate height
            switch (heightMode) {
                case MeasureSpec.EXACTLY:
                case MeasureSpec.AT_MOST:
                    if (heightSize < desiredMinHeight) {
                        mDrawLabels = false;
                    } else {
                        mDrawLabels = true;
                        mSeekBarRect.top = desiredMinHeight;
                        mSeekBarRect.bottom = heightSize > mDefaultSeekBarHeight ? (desiredMinHeight + mDefaultSeekBarHeight) : heightSize;
                    }
                    measuredHeight = (heightSize > (desiredMinHeight + mDefaultSeekBarHeight)) ? (desiredMinHeight + mDefaultSeekBarHeight) : heightSize;
                    break;

                case MeasureSpec.UNSPECIFIED:
                    mDrawLabels = true;
                    measuredHeight = desiredMinHeight + mDefaultSeekBarHeight;
                    mSeekBarRect.top = desiredMinHeight;
                    mSeekBarRect.bottom = measuredHeight;
                    break;
            }
        } else {
            switch (heightMode) {
                case MeasureSpec.EXACTLY:
                case MeasureSpec.AT_MOST:
                    measuredHeight = heightSize;
                    break;

                case MeasureSpec.UNSPECIFIED:
                    measuredHeight = mDefaultSeekBarHeight;
                    break;
            }
        }

        if (!mDrawLabels) {
            // define SeekBar rect
            mSeekBarRect.set(0, 0, measuredWidth, measuredHeight);
        }

        mSeekBar.measure(MeasureSpec.makeMeasureSpec(mSeekBarRect.width(), MeasureSpec.EXACTLY),
                MeasureSpec.makeMeasureSpec(mSeekBarRect.height(), MeasureSpec.EXACTLY));

        setMeasuredDimension(measuredWidth, measuredHeight);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected void dispatchDraw(final Canvas canvas) {
        if (mDrawLabels) {
            final int height = Math.max(mLeftTextBound.height(), mRightTextBound.height());

            canvas.drawText(mLeftLabel, 0, height, mTextPaint);
            canvas.drawText(mRightLabel, getMeasuredWidth() - mRightTextBound.width(), height, mTextPaint);
        }

        super.dispatchDraw(canvas);
    }

    /**
     * Any layout manager that doesn't scroll will want this.
     */
    @Override
    public boolean shouldDelayChildPressedState() {
        return false;
    }
}