Andriod课程设计(5)

import android.os.Bundle;

import android.view.MotionEvent; import android.view.View;

public class ColorPickerDialog extends Dialog { String title; 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;

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

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}

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 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;

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}

}

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, String str) {

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}

}

super(context);

mListener = listener;

mInitialColor = initialColor; title = str;

@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(title);

3.3运行效果图

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