設置引力和填充的視圖

Question

我一直在尋找如何實現一個顏色選擇器，我發現this
@Raghunandan很好的解答，很好地工作。

唯一的問題是：

我不能集中在對話框中的視圖，它一直在上面|留下對話框。我甚至無法設置填充。任何人都知道如何解決這個問題？

如果可能的話我怎麼可以改變對話框主題霍洛（黑色），我的整個應用程序中使用這個主題。

將帖子

的代碼是：

public class ColorPickerDialog extends Dialog { 

public interface OnColorChangedListener { 
    void colorChanged(int color); 
} 

private OnColorChangedListener mListener; 
private int mInitialColor; 

private static class ColorPickerView extends View { 
    private Paint mPaint; 
    private Paint mCenterPaint; 
    private final int[] mColors; 
    private OnColorChangedListener mListener; 

    ColorPickerView(Context c, OnColorChangedListener l, int color) { 
     super(c); 
     mListener = l; 
     mColors = new int[] { 
      0xFFFF0000, 0xFFFF00FF, 0xFF0000FF, 0xFF00FFFF, 0xFF00FF00, 
      0xFFFFFF00, 0xFFFF0000 
     }; 
     Shader s = new SweepGradient(0, 0, mColors, null); 

     mPaint = new Paint(Paint.ANTI_ALIAS_FLAG); 
     mPaint.setShader(s); 
     mPaint.setStyle(Paint.Style.STROKE); 
     mPaint.setStrokeWidth(32); 

     mCenterPaint = new Paint(Paint.ANTI_ALIAS_FLAG); 
     mCenterPaint.setColor(color); 
     mCenterPaint.setStrokeWidth(5); 
    } 

    private boolean mTrackingCenter; 
    private boolean mHighlightCenter; 

    @Override 
    protected void onDraw(Canvas canvas) { 
     float r = CENTER_X - mPaint.getStrokeWidth()*0.5f; 

     canvas.translate(CENTER_X, CENTER_X); 

     canvas.drawOval(new RectF(-r, -r, r, r), mPaint); 
     canvas.drawCircle(0, 0, CENTER_RADIUS, mCenterPaint); 

     if (mTrackingCenter) { 
      int c = mCenterPaint.getColor(); 
      mCenterPaint.setStyle(Paint.Style.STROKE); 

      if (mHighlightCenter) { 
       mCenterPaint.setAlpha(0xFF); 
      } else { 
       mCenterPaint.setAlpha(0x80); 
      } 
      canvas.drawCircle(0, 0, 
           CENTER_RADIUS + mCenterPaint.getStrokeWidth(), 
           mCenterPaint); 

      mCenterPaint.setStyle(Paint.Style.FILL); 
      mCenterPaint.setColor(c); 
     } 
    } 

    @Override 
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { 
     setMeasuredDimension(CENTER_X*2, CENTER_Y*2); 
    } 

    private static final int CENTER_X = 100; 
    private static final int CENTER_Y = 100; 
    private static final int CENTER_RADIUS = 32; 

    private int floatToByte(float x) { 
     int n = java.lang.Math.round(x); 
     return n; 
    } 
    private int pinToByte(int n) { 
     if (n < 0) { 
      n = 0; 
     } else if (n > 255) { 
      n = 255; 
     } 
     return n; 
    } 

    private int ave(int s, int d, float p) { 
     return s + java.lang.Math.round(p * (d - s)); 
    } 

    private int interpColor(int colors[], float unit) { 
     if (unit <= 0) { 
      return colors[0]; 
     } 
     if (unit >= 1) { 
      return colors[colors.length - 1]; 
     } 

     float p = unit * (colors.length - 1); 
     int i = (int)p; 
     p -= i; 

     // now p is just the fractional part [0...1) and i is the index 
     int c0 = colors[i]; 
     int c1 = colors[i+1]; 
     int a = ave(Color.alpha(c0), Color.alpha(c1), p); 
     int r = ave(Color.red(c0), Color.red(c1), p); 
     int g = ave(Color.green(c0), Color.green(c1), p); 
     int b = ave(Color.blue(c0), Color.blue(c1), p); 

     return Color.argb(a, r, g, b); 
    } 

    private int rotateColor(int color, float rad) { 
     float deg = rad * 180/3.1415927f; 
     int r = Color.red(color); 
     int g = Color.green(color); 
     int b = Color.blue(color); 

     ColorMatrix cm = new ColorMatrix(); 
     ColorMatrix tmp = new ColorMatrix(); 

     cm.setRGB2YUV(); 
     tmp.setRotate(0, deg); 
     cm.postConcat(tmp); 
     tmp.setYUV2RGB(); 
     cm.postConcat(tmp); 

     final float[] a = cm.getArray(); 

     int ir = floatToByte(a[0] * r + a[1] * g + a[2] * b); 
     int ig = floatToByte(a[5] * r + a[6] * g + a[7] * b); 
     int ib = floatToByte(a[10] * r + a[11] * g + a[12] * b); 

     return Color.argb(Color.alpha(color), pinToByte(ir), 
          pinToByte(ig), pinToByte(ib)); 
    } 

    private static final float PI = 3.1415926f; 

    @Override 
    public boolean onTouchEvent(MotionEvent event) { 
     float x = event.getX() - CENTER_X; 
     float y = event.getY() - CENTER_Y; 
     boolean inCenter = java.lang.Math.sqrt(x*x + y*y) <= CENTER_RADIUS; 

     switch (event.getAction()) { 
      case MotionEvent.ACTION_DOWN: 
       mTrackingCenter = inCenter; 
       if (inCenter) { 
        mHighlightCenter = true; 
        invalidate(); 
        break; 
       } 
      case MotionEvent.ACTION_MOVE: 
       if (mTrackingCenter) { 
        if (mHighlightCenter != inCenter) { 
         mHighlightCenter = inCenter; 
         invalidate(); 
        } 
       } else { 
        float angle = (float)java.lang.Math.atan2(y, x); 
        // need to turn angle [-PI ... PI] into unit [0....1] 
        float unit = angle/(2*PI); 
        if (unit < 0) { 
         unit += 1; 
        } 
        mCenterPaint.setColor(interpColor(mColors, unit)); 
        invalidate(); 
       } 
       break; 
      case MotionEvent.ACTION_UP: 
       if (mTrackingCenter) { 
        if (inCenter) { 
         mListener.colorChanged(mCenterPaint.getColor()); 
        } 
        mTrackingCenter = false; // so we draw w/o halo 
        invalidate(); 
       } 
       break; 
     } 
     return true; 
    } 
} 

public ColorPickerDialog(Context context, 
         OnColorChangedListener listener, 
         int initialColor) { 
    super(context); 

    mListener = listener; 
    mInitialColor = initialColor; 
} 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    OnColorChangedListener l = new OnColorChangedListener() { 
     public void colorChanged(int color) { 
      mListener.colorChanged(color); 
      dismiss(); 
     } 
    }; 

    setContentView(new ColorPickerView(getContext(), l, mInitialColor)); 
    setTitle("Pick a Color"); 
} 
} 

和EXIB對話框：

button.setOnClickListener(new OnClickListener(){ 
    public void OnClick(View v){ 
      //param - context/listener/inicialColor 
      new ColorPickerDialog(MainActivity.this, this, Color.RED).show(); 
    } 
}); 

Answer 1

選項1：

在您可以將您的自定義視圖像這樣覆蓋onSizeChanged：

@Override 
protected void onSizeChanged(int w, int h, int oldw, int oldh) { 
    width = w; 
    height = h; 

    // Move your calculation logic here. 
    super.onSizeChanged(w, h, oldw, oldh); 
} 

通過這種方式，您可以將視圖的大小設置爲對話框的內容。

int centerX = widht/2; 
int centerY = height/2; 
int offset = *Your required view size here*/2; 
canvas.drawOval(new RectF(centerX - offset, 0, centerX + offset, height), mPaint); 
canvas.drawCircle(centerX, centerY, CENTER_RADIUS, mCenterPaint); 

這樣的觀點：在你的onDraw（）方法，知道了這一點，你可以很容易地通過使用寬度/ 2，高度/ 2.您繪製調用可以修改在中心繪製計算視圖的中心將水平繪製居中，並填充所有高度。如果需要，也可以按照與矩形的左右座標相同的方式對其進行垂直居中。此外，避免在onDraw（）方法中分配對象是一種很好的做法，因爲取決於視圖，它可能會被調用很多次（在動畫等過程中）。只要知道視圖的大小並且位於onSizeChanged（）中，就可以計算出您的RectF。

選項2：

你或許可以避免將其添加到對話時，只設置正確的佈局參數修改自定義視圖。如果我沒有記錯，Dialog使用ViewGroup.LayoutParams。他們沒有重力場。所以在你的對話框中創建你可以把你的視圖包裹在一個LinearLayout或其他任何支持重力和設置中心重力的視圖中：

LinearLayout layout = new LinearLayout(getContext()); 

YourView view = new ColorPickerView(getContext(), l, mInitialColor); 
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(*Width of you view or wrap_content*,*height of your view or wrap_content*); 
params.gravity = Gravity.CENTER_HORIZONTAL; 
view.setLayoutParams(params); 

layout.addView(view) 
setContentView(layout);