// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
package org.chromium.ui;
import android.app.Dialog;
import android.content.Context;
import android.content.DialogInterface;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.RectF;
import android.graphics.Shader;
import android.graphics.SweepGradient;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
/**
* UI for the color chooser that shows on the Android platform as a result
* of <input type=color > form element.
*
* <p> Note that this UI is only temporary and will be replaced once the UI
* design in
* https://code.google.com/p/chromium/issues/detail?id=162491 is finalized
*/
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 static final int CENTER_RADIUS = 32;
private static final int DIALOG_HEIGHT = 200;
private static final int BOUNDING_BOX_EDGE = 100;
private static final float PI = 3.1415926f;
private final Paint mPaint;
private final Paint mCenterPaint;
private final int[] mColors;
private final OnColorChangedListener mListener;
private boolean mTrackingCenter;
private boolean mHighlightCenter;
private int center_x = -1;
private int center_y = -1;
ColorPickerView(Context c, OnColorChangedListener listener, int color) {
super(c);
mListener = listener;
mColors = new int[] {
0xFFFF0000, 0xFFFF00FF, 0xFF0000FF, 0xFF00FFFF, 0xFF00FF00,
0xFFFFFF00, 0xFFFF0000
};
Shader shader = new SweepGradient(0, 0, mColors, null);
mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mPaint.setShader(shader);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeWidth(32);
mCenterPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mCenterPaint.setColor(color);
mCenterPaint.setStrokeWidth(5);
}
@Override
protected void onDraw(Canvas canvas) {
if (center_x == -1) {
center_x = getWidth() / 2;
}
if (center_y == -1) {
center_y = getHeight() / 2;
}
float r = BOUNDING_BOX_EDGE - mPaint.getStrokeWidth() * 0.5f;
canvas.translate(center_x, center_y);
canvas.drawOval(new RectF(-r, -r, r, r), mPaint);
canvas.drawCircle(0, 0, CENTER_RADIUS, mCenterPaint);
if (mTrackingCenter) {
int color = 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(color);
}
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
setMeasuredDimension(widthMeasureSpec, DIALOG_HEIGHT);
}
private static int interpolate(int low, int high, float interPolant) {
return low + java.lang.Math.round(interPolant * (high - low));
}
static int interpolateColor(int colors[], float x, float y) {
float angle = (float)java.lang.Math.atan2(y, x);
float unit = angle / (2 * PI);
if (unit < 0) {
unit += 1;
}
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 = interpolate(Color.alpha(c0), Color.alpha(c1), p);
int r = interpolate(Color.red(c0), Color.red(c1), p);
int g = interpolate(Color.green(c0), Color.green(c1), p);
int b = interpolate(Color.blue(c0), Color.blue(c1), p);
return Color.argb(a, r, g, b);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
float x = event.getX() - center_x;
float y = event.getY() - center_y;
// equivalent to sqrt(x * x + y * y) <= CENTER_RADIUS but cheaper
boolean inCenter = (x * x + y * y) <= (CENTER_RADIUS * 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 {
mCenterPaint.setColor(interpolateColor(mColors, x, y));
invalidate();
}
break;
case MotionEvent.ACTION_UP:
if (mTrackingCenter) {
if (inCenter) {
mListener.colorChanged(mCenterPaint.getColor());
}
// Draw without the halo surrounding the central circle.
mTrackingCenter = false;
invalidate();
}
break;
default:
break;
}
return true;
}
}
public ColorPickerDialog(Context context,
OnColorChangedListener listener,
int initialColor) {
super(context);
mListener = listener;
mInitialColor = initialColor;
setOnCancelListener(new DialogInterface.OnCancelListener() {
@Override
public void onCancel(DialogInterface arg0) {
mListener.colorChanged(mInitialColor);
}
});
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(new ColorPickerView(getContext(), mListener, mInitialColor));
// TODO(miguelg): Internationalization
setTitle("Select Color");
}
}