OmniLib: Introduce OmniRom SDK

 * omnilib-res app will be installed to system/frameworks for the futur internal ressources add-on
 * OmniLib java_library will be installed to system/frameworks for the futur internal java/aidl add-on
 * The OmniPreference android_library need to be moved outside system/frameworks  because of some nested dependency breakage

Change-Id: I2b9a7bc7f4aa72052ae6600933eb114d2a481b35

omnilib-res: Add allow-reserved-package-id

Thx to the LineageOS team

https://github.com/LineageOS/android_lineage-sdk/blob/lineage-20.0/Android.bp#L44-L49

Change-Id: I07ba56685981a8735bdef5ea75528ec82dd68318
diff --git a/omnipreference/java/omnirom/ui/AlphaPatternDrawable.java b/omnipreference/java/omnirom/ui/AlphaPatternDrawable.java
new file mode 100644
index 0000000..d91998d
--- /dev/null
+++ b/omnipreference/java/omnirom/ui/AlphaPatternDrawable.java
@@ -0,0 +1,125 @@
+/*
+ * Copyright (C) 2010 Daniel Nilsson
+ * Copyright (C) 2012 The CyanogenMod Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package omnirom.ui;
+
+import android.graphics.Bitmap;
+import android.graphics.Canvas;
+import android.graphics.ColorFilter;
+import android.graphics.Paint;
+import android.graphics.Rect;
+import android.graphics.Bitmap.Config;
+import android.graphics.drawable.Drawable;
+
+/**
+ * This drawable that draws a simple white and gray chess board pattern. It's
+ * pattern you will often see as a background behind a partly transparent image
+ * in many applications.
+ *
+ * @author Daniel Nilsson
+ */
+public class AlphaPatternDrawable extends Drawable {
+
+    private int mRectangleSize = 10;
+
+    private Paint mPaint = new Paint();
+    private Paint mPaintWhite = new Paint();
+    private Paint mPaintGray = new Paint();
+
+    private int numRectanglesHorizontal;
+    private int numRectanglesVertical;
+
+    /**
+     * Bitmap in which the pattern will be cached.
+     */
+    private Bitmap mBitmap;
+
+    public AlphaPatternDrawable(int rectangleSize) {
+        mRectangleSize = rectangleSize;
+        mPaintWhite.setColor(0xffffffff);
+        mPaintGray.setColor(0xffcbcbcb);
+    }
+
+    @Override
+    public void draw(Canvas canvas) {
+        if (mBitmap != null) {
+            canvas.drawBitmap(mBitmap, null, getBounds(), mPaint);
+        }
+    }
+
+    @Override
+    public int getOpacity() {
+        return 0;
+    }
+
+    @Override
+    public void setAlpha(int alpha) {
+        throw new UnsupportedOperationException("Alpha is not supported by this drawwable.");
+    }
+
+    @Override
+    public void setColorFilter(ColorFilter cf) {
+        throw new UnsupportedOperationException("ColorFilter is not supported by this drawwable.");
+    }
+
+    @Override
+    protected void onBoundsChange(Rect bounds) {
+        super.onBoundsChange(bounds);
+
+        int height = bounds.height();
+        int width = bounds.width();
+
+        numRectanglesHorizontal = (int) Math.ceil((width / mRectangleSize));
+        numRectanglesVertical = (int) Math.ceil(height / mRectangleSize);
+
+        generatePatternBitmap();
+    }
+
+    /**
+     * This will generate a bitmap with the pattern as big as the rectangle we
+     * were allow to draw on. We do this to cache the bitmap so we don't need
+     * to recreate it each time draw() is called since it takes a few
+     * milliseconds.
+     */
+    private void generatePatternBitmap() {
+
+        if (getBounds().width() <= 0 || getBounds().height() <= 0) {
+            return;
+        }
+
+        mBitmap = Bitmap.createBitmap(getBounds().width(), getBounds().height(), Config.ARGB_8888);
+        Canvas canvas = new Canvas(mBitmap);
+
+        Rect r = new Rect();
+        boolean verticalStartWhite = true;
+        for (int i = 0; i <= numRectanglesVertical; i++) {
+            boolean isWhite = verticalStartWhite;
+            for (int j = 0; j <= numRectanglesHorizontal; j++) {
+                r.top = i * mRectangleSize;
+                r.left = j * mRectangleSize;
+                r.bottom = r.top + mRectangleSize;
+                r.right = r.left + mRectangleSize;
+
+                canvas.drawRect(r, isWhite ? mPaintWhite : mPaintGray);
+
+                isWhite = !isWhite;
+            }
+
+            verticalStartWhite = !verticalStartWhite;
+        }
+    }
+}
diff --git a/omnipreference/java/omnirom/ui/ColorPanelView.java b/omnipreference/java/omnirom/ui/ColorPanelView.java
new file mode 100644
index 0000000..e50ce86
--- /dev/null
+++ b/omnipreference/java/omnirom/ui/ColorPanelView.java
@@ -0,0 +1,171 @@
+/*
+ * Copyright (C) 2010 Daniel Nilsson
+ * Copyright (C) 2012 The CyanogenMod Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package omnirom.ui;
+
+import android.content.Context;
+import android.graphics.Canvas;
+import android.graphics.Paint;
+import android.graphics.RectF;
+import android.util.AttributeSet;
+import android.view.View;
+
+/**
+ * This class draws a panel which which will be filled with a color which can be
+ * set. It can be used to show the currently selected color which you will get
+ * from the {@link ColorPickerView}.
+ *
+ * @author Daniel Nilsson
+ */
+public class ColorPanelView extends View {
+
+    /**
+     * The width in pixels of the border surrounding the color panel.
+     */
+    private final static float BORDER_WIDTH_PX = 1;
+
+    private static float mDensity = 1f;
+
+    private int mBorderColor = 0xff6E6E6E;
+    private int mColor = 0xff000000;
+
+    private Paint mBorderPaint;
+    private Paint mColorPaint;
+
+    private RectF mDrawingRect;
+    private RectF mColorRect;
+
+    private AlphaPatternDrawable mAlphaPattern;
+
+    public ColorPanelView(Context context) {
+        this(context, null);
+    }
+
+    public ColorPanelView(Context context, AttributeSet attrs) {
+        this(context, attrs, 0);
+    }
+
+    public ColorPanelView(Context context, AttributeSet attrs, int defStyle) {
+        super(context, attrs, defStyle);
+
+        init();
+    }
+
+    private void init() {
+        mBorderPaint = new Paint();
+        mColorPaint = new Paint();
+        mDensity = getContext().getResources().getDisplayMetrics().density;
+    }
+
+    @Override
+    protected void onDraw(Canvas canvas) {
+
+        final RectF rect = mColorRect;
+
+        if (BORDER_WIDTH_PX > 0) {
+            mBorderPaint.setColor(mBorderColor);
+            canvas.drawRect(mDrawingRect, mBorderPaint);
+        }
+
+        if (mAlphaPattern != null) {
+            mAlphaPattern.draw(canvas);
+        }
+
+        mColorPaint.setColor(mColor);
+
+        canvas.drawRect(rect, mColorPaint);
+    }
+
+    @Override
+    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+
+        int width = MeasureSpec.getSize(widthMeasureSpec);
+        int height = MeasureSpec.getSize(heightMeasureSpec);
+
+        setMeasuredDimension(width, height);
+    }
+
+    @Override
+    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
+        super.onSizeChanged(w, h, oldw, oldh);
+
+        mDrawingRect = new RectF();
+        mDrawingRect.left = getPaddingLeft();
+        mDrawingRect.right = w - getPaddingRight();
+        mDrawingRect.top = getPaddingTop();
+        mDrawingRect.bottom = h - getPaddingBottom();
+
+        setUpColorRect();
+
+    }
+
+    private void setUpColorRect() {
+        final RectF dRect = mDrawingRect;
+
+        float left = dRect.left + BORDER_WIDTH_PX;
+        float top = dRect.top + BORDER_WIDTH_PX;
+        float bottom = dRect.bottom - BORDER_WIDTH_PX;
+        float right = dRect.right - BORDER_WIDTH_PX;
+
+        mColorRect = new RectF(left, top, right, bottom);
+
+        mAlphaPattern = new AlphaPatternDrawable((int) (5 * mDensity));
+
+        mAlphaPattern.setBounds(Math.round(mColorRect.left),
+                Math.round(mColorRect.top),
+                Math.round(mColorRect.right),
+                Math.round(mColorRect.bottom));
+
+    }
+
+    /**
+     * Set the color that should be shown by this view.
+     *
+     * @param color
+     */
+    public void setColor(int color) {
+        mColor = color;
+        invalidate();
+    }
+
+    /**
+     * Get the color currently show by this view.
+     *
+     * @return
+     */
+    public int getColor() {
+        return mColor;
+    }
+
+    /**
+     * Set the color of the border surrounding the panel.
+     *
+     * @param color
+     */
+    public void setBorderColor(int color) {
+        mBorderColor = color;
+        invalidate();
+    }
+
+    /**
+     * Get the color of the border surrounding the panel.
+     */
+    public int getBorderColor() {
+        return mBorderColor;
+    }
+
+}
diff --git a/omnipreference/java/omnirom/ui/ColorPickerView.java b/omnipreference/java/omnirom/ui/ColorPickerView.java
new file mode 100644
index 0000000..e703181
--- /dev/null
+++ b/omnipreference/java/omnirom/ui/ColorPickerView.java
@@ -0,0 +1,841 @@
+/*
+ * Copyright (C) 2010 Daniel Nilsson
+ * Copyright (C) 2012 The CyanogenMod Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package omnirom.ui;
+
+import android.content.Context;
+import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.ComposeShader;
+import android.graphics.LinearGradient;
+import android.graphics.Paint;
+import android.graphics.Point;
+import android.graphics.PorterDuff.Mode;
+import android.graphics.RectF;
+import android.graphics.Shader;
+import android.graphics.Paint.Align;
+import android.graphics.Paint.Style;
+import android.graphics.Shader.TileMode;
+import android.os.Build;
+import android.util.AttributeSet;
+import android.view.MotionEvent;
+import android.view.View;
+
+/**
+ * Displays a color picker to the user and allow them to select a color. A
+ * slider for the alpha channel is also available. Enable it by setting
+ * setAlphaSliderVisible(boolean) to true.
+ *
+ * @author Daniel Nilsson
+ */
+public class ColorPickerView extends View {
+
+    public interface OnColorChangedListener {
+        public void onColorChanged(int color);
+    }
+
+    private final static int PANEL_SAT_VAL = 0;
+    private final static int PANEL_HUE = 1;
+    private final static int PANEL_ALPHA = 2;
+
+    /**
+     * The width in pixels of the border surrounding all color panels.
+     */
+    private final static float BORDER_WIDTH_PX = 1;
+
+    /**
+     * The width in dp of the hue panel.
+     */
+    private float HUE_PANEL_WIDTH = 30f;
+    /**
+     * The height in dp of the alpha panel
+     */
+    private float ALPHA_PANEL_HEIGHT = 20f;
+    /**
+     * The distance in dp between the different color panels.
+     */
+    private float PANEL_SPACING = 10f;
+    /**
+     * The radius in dp of the color palette tracker circle.
+     */
+    private float PALETTE_CIRCLE_TRACKER_RADIUS = 5f;
+    /**
+     * The dp which the tracker of the hue or alpha panel will extend outside of
+     * its bounds.
+     */
+    private float RECTANGLE_TRACKER_OFFSET = 2f;
+
+    private static float mDensity = 1f;
+
+    private OnColorChangedListener mListener;
+
+    private Paint mSatValPaint;
+    private Paint mSatValTrackerPaint;
+
+    private Paint mHuePaint;
+    private Paint mHueTrackerPaint;
+
+    private Paint mAlphaPaint;
+    private Paint mAlphaTextPaint;
+
+    private Paint mBorderPaint;
+
+    private Shader mValShader;
+    private Shader mSatShader;
+    private Shader mHueShader;
+    private Shader mAlphaShader;
+
+    private int mAlpha = 0xff;
+    private float mHue = 360f;
+    private float mSat = 0f;
+    private float mVal = 0f;
+
+    private String mAlphaSliderText = "Alpha";
+    private int mSliderTrackerColor = 0xff1c1c1c;
+    private int mBorderColor = 0xff6E6E6E;
+    private boolean mShowAlphaPanel = false;
+
+    /*
+     * To remember which panel that has the "focus" when processing hardware
+     * button data.
+     */
+    private int mLastTouchedPanel = PANEL_SAT_VAL;
+
+    /**
+     * Offset from the edge we must have or else the finger tracker will get
+     * clipped when it is drawn outside of the view.
+     */
+    private float mDrawingOffset;
+
+    /*
+     * Distance form the edges of the view of where we are allowed to draw.
+     */
+    private RectF mDrawingRect;
+
+    private RectF mSatValRect;
+    private RectF mHueRect;
+    private RectF mAlphaRect;
+
+    private AlphaPatternDrawable mAlphaPattern;
+
+    private Point mStartTouchPoint = null;
+
+    public ColorPickerView(Context context) {
+        this(context, null);
+    }
+
+    public ColorPickerView(Context context, AttributeSet attrs) {
+        this(context, attrs, 0);
+    }
+
+    public ColorPickerView(Context context, AttributeSet attrs, int defStyle) {
+        super(context, attrs, defStyle);
+        init();
+    }
+
+    private void init() {
+        mDensity = getContext().getResources().getDisplayMetrics().density;
+        PALETTE_CIRCLE_TRACKER_RADIUS *= mDensity;
+        RECTANGLE_TRACKER_OFFSET *= mDensity;
+        HUE_PANEL_WIDTH *= mDensity;
+        ALPHA_PANEL_HEIGHT *= mDensity;
+        PANEL_SPACING = PANEL_SPACING * mDensity;
+
+        mDrawingOffset = calculateRequiredOffset();
+        initPaintTools();
+
+        // Needed for receiving track ball motion events.
+        setFocusableInTouchMode(true);
+        setFocusable(true);
+        setClickable(true);
+    }
+
+    private void initPaintTools() {
+        mSatValPaint = new Paint();
+        mSatValTrackerPaint = new Paint();
+        mHuePaint = new Paint();
+        mHueTrackerPaint = new Paint();
+        mAlphaPaint = new Paint();
+        mAlphaTextPaint = new Paint();
+        mBorderPaint = new Paint();
+
+        mSatValTrackerPaint.setStyle(Style.STROKE);
+        mSatValTrackerPaint.setStrokeWidth(2f * mDensity);
+        mSatValTrackerPaint.setAntiAlias(true);
+
+        mHueTrackerPaint.setColor(mSliderTrackerColor);
+        mHueTrackerPaint.setStyle(Style.STROKE);
+        mHueTrackerPaint.setStrokeWidth(2f * mDensity);
+        mHueTrackerPaint.setAntiAlias(true);
+
+        mAlphaTextPaint.setColor(0xff1c1c1c);
+        mAlphaTextPaint.setTextSize(14f * mDensity);
+        mAlphaTextPaint.setAntiAlias(true);
+        mAlphaTextPaint.setTextAlign(Align.CENTER);
+        mAlphaTextPaint.setFakeBoldText(true);
+    }
+
+    private float calculateRequiredOffset() {
+        float offset = Math.max(PALETTE_CIRCLE_TRACKER_RADIUS, RECTANGLE_TRACKER_OFFSET);
+        offset = Math.max(offset, BORDER_WIDTH_PX * mDensity);
+
+        return offset * 1.5f;
+    }
+
+    private int[] buildHueColorArray() {
+        int[] hue = new int[361];
+
+        int count = 0;
+        for (int i = hue.length - 1; i >= 0; i--, count++) {
+            hue[count] = Color.HSVToColor(new float[] {
+                    i, 1f, 1f
+            });
+        }
+        return hue;
+    }
+
+    @Override
+    protected void onDraw(Canvas canvas) {
+        if (mDrawingRect.width() <= 0 || mDrawingRect.height() <= 0) {
+            return;
+        }
+        drawSatValPanel(canvas);
+        drawHuePanel(canvas);
+        drawAlphaPanel(canvas);
+    }
+
+    private void drawSatValPanel(Canvas canvas) {
+        final RectF rect = mSatValRect;
+        int rgb = Color.HSVToColor(new float[] {
+                mHue, 1f, 1f
+        });
+
+        if (BORDER_WIDTH_PX > 0) {
+            mBorderPaint.setColor(mBorderColor);
+            canvas.drawRect(mDrawingRect.left, mDrawingRect.top, rect.right + BORDER_WIDTH_PX,
+                    rect.bottom + BORDER_WIDTH_PX, mBorderPaint);
+        }
+
+        // On Honeycomb+ we need to use software rendering to create the shader properly
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
+            setLayerType(View.LAYER_TYPE_SOFTWARE, null);
+        }
+
+        // Get the overlaying gradients ready and create the ComposeShader
+        if (mValShader == null) {
+            mValShader = new LinearGradient(rect.left, rect.top, rect.left, rect.bottom,
+                    0xffffffff, 0xff000000, TileMode.CLAMP);
+        }
+        mSatShader = new LinearGradient(rect.left, rect.top, rect.right, rect.top,
+                0xffffffff, rgb, TileMode.CLAMP);
+        ComposeShader mShader = new ComposeShader(mValShader, mSatShader, Mode.MULTIPLY);
+        mSatValPaint.setShader(mShader);
+        canvas.drawRect(rect, mSatValPaint);
+
+        Point p = satValToPoint(mSat, mVal);
+        mSatValTrackerPaint.setColor(0xff000000);
+        canvas.drawCircle(p.x, p.y, PALETTE_CIRCLE_TRACKER_RADIUS - 1f * mDensity,
+                mSatValTrackerPaint);
+
+        mSatValTrackerPaint.setColor(0xffdddddd);
+        canvas.drawCircle(p.x, p.y, PALETTE_CIRCLE_TRACKER_RADIUS, mSatValTrackerPaint);
+    }
+
+    private void drawHuePanel(Canvas canvas) {
+        final RectF rect = mHueRect;
+
+        if (BORDER_WIDTH_PX > 0) {
+            mBorderPaint.setColor(mBorderColor);
+            canvas.drawRect(rect.left - BORDER_WIDTH_PX,
+                    rect.top - BORDER_WIDTH_PX,
+                    rect.right + BORDER_WIDTH_PX,
+                    rect.bottom + BORDER_WIDTH_PX,
+                    mBorderPaint);
+        }
+
+        if (mHueShader == null) {
+            mHueShader = new LinearGradient(rect.left, rect.top, rect.left, rect.bottom,
+                    buildHueColorArray(), null, TileMode.CLAMP);
+            mHuePaint.setShader(mHueShader);
+        }
+
+        canvas.drawRect(rect, mHuePaint);
+
+        float rectHeight = 4 * mDensity / 2;
+
+        Point p = hueToPoint(mHue);
+
+        RectF r = new RectF();
+        r.left = rect.left - RECTANGLE_TRACKER_OFFSET;
+        r.right = rect.right + RECTANGLE_TRACKER_OFFSET;
+        r.top = p.y - rectHeight;
+        r.bottom = p.y + rectHeight;
+
+        canvas.drawRoundRect(r, 2, 2, mHueTrackerPaint);
+
+    }
+
+    private void drawAlphaPanel(Canvas canvas) {
+        if (!mShowAlphaPanel || mAlphaRect == null || mAlphaPattern == null) {
+            return;
+        }
+
+        final RectF rect = mAlphaRect;
+
+        if (BORDER_WIDTH_PX > 0) {
+            mBorderPaint.setColor(mBorderColor);
+            canvas.drawRect(rect.left - BORDER_WIDTH_PX,
+                    rect.top - BORDER_WIDTH_PX,
+                    rect.right + BORDER_WIDTH_PX,
+                    rect.bottom + BORDER_WIDTH_PX,
+                    mBorderPaint);
+        }
+
+        mAlphaPattern.draw(canvas);
+
+        float[] hsv = new float[] {
+                mHue, mSat, mVal
+        };
+        int color = Color.HSVToColor(hsv);
+        int acolor = Color.HSVToColor(0, hsv);
+
+        mAlphaShader = new LinearGradient(rect.left, rect.top, rect.right, rect.top,
+                color, acolor, TileMode.CLAMP);
+
+        mAlphaPaint.setShader(mAlphaShader);
+
+        canvas.drawRect(rect, mAlphaPaint);
+
+        if (mAlphaSliderText != null && mAlphaSliderText != "") {
+            canvas.drawText(mAlphaSliderText, rect.centerX(), rect.centerY() + 4 * mDensity,
+                    mAlphaTextPaint);
+        }
+
+        float rectWidth = 4 * mDensity / 2;
+        Point p = alphaToPoint(mAlpha);
+
+        RectF r = new RectF();
+        r.left = p.x - rectWidth;
+        r.right = p.x + rectWidth;
+        r.top = rect.top - RECTANGLE_TRACKER_OFFSET;
+        r.bottom = rect.bottom + RECTANGLE_TRACKER_OFFSET;
+
+        canvas.drawRoundRect(r, 2, 2, mHueTrackerPaint);
+    }
+
+    private Point hueToPoint(float hue) {
+        final RectF rect = mHueRect;
+        final float height = rect.height();
+
+        Point p = new Point();
+        p.y = (int) (height - (hue * height / 360f) + rect.top);
+        p.x = (int) rect.left;
+        return p;
+    }
+
+    private Point satValToPoint(float sat, float val) {
+
+        final RectF rect = mSatValRect;
+        final float height = rect.height();
+        final float width = rect.width();
+
+        Point p = new Point();
+
+        p.x = (int) (sat * width + rect.left);
+        p.y = (int) ((1f - val) * height + rect.top);
+
+        return p;
+    }
+
+    private Point alphaToPoint(int alpha) {
+        final RectF rect = mAlphaRect;
+        final float width = rect.width();
+
+        Point p = new Point();
+        p.x = (int) (width - (alpha * width / 0xff) + rect.left);
+        p.y = (int) rect.top;
+        return p;
+    }
+
+    private float[] pointToSatVal(float x, float y) {
+        final RectF rect = mSatValRect;
+        float[] result = new float[2];
+        float width = rect.width();
+        float height = rect.height();
+
+        if (x < rect.left) {
+            x = 0f;
+        } else if (x > rect.right) {
+            x = width;
+        } else {
+            x = x - rect.left;
+        }
+
+        if (y < rect.top) {
+            y = 0f;
+        } else if (y > rect.bottom) {
+            y = height;
+        } else {
+            y = y - rect.top;
+        }
+
+        result[0] = 1.f / width * x;
+        result[1] = 1.f - (1.f / height * y);
+        return result;
+    }
+
+    private float pointToHue(float y) {
+        final RectF rect = mHueRect;
+        float height = rect.height();
+
+        if (y < rect.top) {
+            y = 0f;
+        } else if (y > rect.bottom) {
+            y = height;
+        } else {
+            y = y - rect.top;
+        }
+        return 360f - (y * 360f / height);
+    }
+
+    private int pointToAlpha(int x) {
+        final RectF rect = mAlphaRect;
+        final int width = (int) rect.width();
+
+        if (x < rect.left) {
+            x = 0;
+        } else if (x > rect.right) {
+            x = width;
+        } else {
+            x = x - (int) rect.left;
+        }
+        return 0xff - (x * 0xff / width);
+    }
+
+    @Override
+    public boolean onTrackballEvent(MotionEvent event) {
+        float x = event.getX();
+        float y = event.getY();
+        boolean update = false;
+
+        if (event.getAction() == MotionEvent.ACTION_MOVE) {
+            switch (mLastTouchedPanel) {
+                case PANEL_SAT_VAL:
+                    float sat,
+                    val;
+                    sat = mSat + x / 50f;
+                    val = mVal - y / 50f;
+                    if (sat < 0f) {
+                        sat = 0f;
+                    } else if (sat > 1f) {
+                        sat = 1f;
+                    }
+
+                    if (val < 0f) {
+                        val = 0f;
+                    } else if (val > 1f) {
+                        val = 1f;
+                    }
+                    mSat = sat;
+                    mVal = val;
+                    update = true;
+                    break;
+                case PANEL_HUE:
+                    float hue = mHue - y * 10f;
+                    if (hue < 0f) {
+                        hue = 0f;
+                    } else if (hue > 360f) {
+                        hue = 360f;
+                    }
+                    mHue = hue;
+                    update = true;
+                    break;
+                case PANEL_ALPHA:
+                    if (!mShowAlphaPanel || mAlphaRect == null) {
+                        update = false;
+                    } else {
+                        int alpha = (int) (mAlpha - x * 10);
+                        if (alpha < 0) {
+                            alpha = 0;
+                        } else if (alpha > 0xff) {
+                            alpha = 0xff;
+                        }
+                        mAlpha = alpha;
+                        update = true;
+                    }
+                    break;
+            }
+        }
+
+        if (update) {
+            if (mListener != null) {
+                mListener.onColorChanged(Color.HSVToColor(mAlpha, new float[] {
+                        mHue, mSat, mVal
+                }));
+            }
+            invalidate();
+            return true;
+        }
+        return super.onTrackballEvent(event);
+    }
+
+    @Override
+    public boolean onTouchEvent(MotionEvent event) {
+        boolean update = false;
+
+        switch (event.getAction()) {
+            case MotionEvent.ACTION_DOWN:
+                mStartTouchPoint = new Point((int) event.getX(), (int) event.getY());
+                update = moveTrackersIfNeeded(event);
+                break;
+            case MotionEvent.ACTION_MOVE:
+                update = moveTrackersIfNeeded(event);
+                break;
+            case MotionEvent.ACTION_UP:
+                mStartTouchPoint = null;
+                update = moveTrackersIfNeeded(event);
+                break;
+        }
+
+        if (update) {
+            requestFocus();
+            if (mListener != null) {
+                mListener.onColorChanged(Color.HSVToColor(mAlpha, new float[] {
+                        mHue, mSat, mVal
+                }));
+            }
+            invalidate();
+            return true;
+        }
+
+        return super.onTouchEvent(event);
+    }
+
+    private boolean moveTrackersIfNeeded(MotionEvent event) {
+
+        if (mStartTouchPoint == null)
+            return false;
+
+        boolean update = false;
+        int startX = mStartTouchPoint.x;
+        int startY = mStartTouchPoint.y;
+
+        if (mHueRect.contains(startX, startY)) {
+            mLastTouchedPanel = PANEL_HUE;
+            mHue = pointToHue(event.getY());
+            update = true;
+        } else if (mSatValRect.contains(startX, startY)) {
+            mLastTouchedPanel = PANEL_SAT_VAL;
+            float[] result = pointToSatVal(event.getX(), event.getY());
+            mSat = result[0];
+            mVal = result[1];
+            update = true;
+        } else if (mAlphaRect != null && mAlphaRect.contains(startX, startY)) {
+            mLastTouchedPanel = PANEL_ALPHA;
+            mAlpha = pointToAlpha((int) event.getX());
+            update = true;
+        }
+
+        return update;
+    }
+
+    @Override
+    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+        int width = 0;
+        int height = 0;
+
+        int widthMode = MeasureSpec.getMode(widthMeasureSpec);
+        int heightMode = MeasureSpec.getMode(heightMeasureSpec);
+
+        int widthAllowed = MeasureSpec.getSize(widthMeasureSpec);
+        int heightAllowed = MeasureSpec.getSize(heightMeasureSpec);
+
+        widthAllowed = chooseWidth(widthMode, widthAllowed);
+        heightAllowed = chooseHeight(heightMode, heightAllowed);
+
+        if (!mShowAlphaPanel) {
+            height = (int) (widthAllowed - PANEL_SPACING - HUE_PANEL_WIDTH);
+
+            // If calculated height (based on the width) is more than the
+            // allowed height.
+            if (height > heightAllowed && heightMode != MeasureSpec.UNSPECIFIED) {
+                height = heightAllowed;
+                width = (int) (height + PANEL_SPACING + HUE_PANEL_WIDTH);
+            } else {
+                width = widthAllowed;
+            }
+        } else {
+
+            width = (int) (heightAllowed - ALPHA_PANEL_HEIGHT + HUE_PANEL_WIDTH);
+
+            if (width > widthAllowed && widthMode != MeasureSpec.UNSPECIFIED) {
+                width = widthAllowed;
+                height = (int) (widthAllowed - HUE_PANEL_WIDTH + ALPHA_PANEL_HEIGHT);
+            } else {
+                height = heightAllowed;
+            }
+        }
+        setMeasuredDimension(width, height);
+    }
+
+    private int chooseWidth(int mode, int size) {
+        if (mode == MeasureSpec.AT_MOST || mode == MeasureSpec.EXACTLY) {
+            return size;
+        } else { // (mode == MeasureSpec.UNSPECIFIED)
+            return getPrefferedWidth();
+        }
+    }
+
+    private int chooseHeight(int mode, int size) {
+        if (mode == MeasureSpec.AT_MOST || mode == MeasureSpec.EXACTLY) {
+            return size;
+        } else { // (mode == MeasureSpec.UNSPECIFIED)
+            return getPrefferedHeight();
+        }
+    }
+
+    private int getPrefferedWidth() {
+        int width = getPrefferedHeight();
+        if (mShowAlphaPanel) {
+            width -= (PANEL_SPACING + ALPHA_PANEL_HEIGHT);
+        }
+        return (int) (width + HUE_PANEL_WIDTH + PANEL_SPACING);
+    }
+
+    private int getPrefferedHeight() {
+        int height = (int) (200 * mDensity);
+        if (mShowAlphaPanel) {
+            height += PANEL_SPACING + ALPHA_PANEL_HEIGHT;
+        }
+        return height;
+    }
+
+    @Override
+    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
+        super.onSizeChanged(w, h, oldw, oldh);
+
+        mDrawingRect = new RectF();
+        mDrawingRect.left = mDrawingOffset + getPaddingLeft();
+        mDrawingRect.right = w - mDrawingOffset - getPaddingRight();
+        mDrawingRect.top = mDrawingOffset + getPaddingTop();
+        mDrawingRect.bottom = h - mDrawingOffset - getPaddingBottom();
+
+        setUpSatValRect();
+        setUpHueRect();
+        setUpAlphaRect();
+    }
+
+    private void setUpSatValRect() {
+        final RectF dRect = mDrawingRect;
+        float panelSide = dRect.height() - BORDER_WIDTH_PX * 2;
+
+        if (mShowAlphaPanel) {
+            panelSide -= PANEL_SPACING + ALPHA_PANEL_HEIGHT;
+        }
+
+        float left = dRect.left + BORDER_WIDTH_PX;
+        float top = dRect.top + BORDER_WIDTH_PX;
+        float bottom = top + panelSide;
+        float right = left + panelSide;
+        mSatValRect = new RectF(left, top, right, bottom);
+    }
+
+    private void setUpHueRect() {
+        final RectF dRect = mDrawingRect;
+
+        float left = dRect.right - HUE_PANEL_WIDTH + BORDER_WIDTH_PX;
+        float top = dRect.top + BORDER_WIDTH_PX;
+        float bottom = dRect.bottom - BORDER_WIDTH_PX
+                - (mShowAlphaPanel ? (PANEL_SPACING + ALPHA_PANEL_HEIGHT) : 0);
+        float right = dRect.right - BORDER_WIDTH_PX;
+
+        mHueRect = new RectF(left, top, right, bottom);
+    }
+
+    private void setUpAlphaRect() {
+        if (!mShowAlphaPanel) {
+            return;
+        }
+
+        final RectF dRect = mDrawingRect;
+        float left = dRect.left + BORDER_WIDTH_PX;
+        float top = dRect.bottom - ALPHA_PANEL_HEIGHT + BORDER_WIDTH_PX;
+        float bottom = dRect.bottom - BORDER_WIDTH_PX;
+        float right = dRect.right - BORDER_WIDTH_PX;
+
+        mAlphaRect = new RectF(left, top, right, bottom);
+        mAlphaPattern = new AlphaPatternDrawable((int) (5 * mDensity));
+        mAlphaPattern.setBounds(Math.round(mAlphaRect.left), Math
+                .round(mAlphaRect.top), Math.round(mAlphaRect.right), Math
+                .round(mAlphaRect.bottom));
+    }
+
+    /**
+     * Set a OnColorChangedListener to get notified when the color selected by
+     * the user has changed.
+     *
+     * @param listener
+     */
+    public void setOnColorChangedListener(OnColorChangedListener listener) {
+        mListener = listener;
+    }
+
+    /**
+     * Set the color of the border surrounding all panels.
+     *
+     * @param color
+     */
+    public void setBorderColor(int color) {
+        mBorderColor = color;
+        invalidate();
+    }
+
+    /**
+     * Get the color of the border surrounding all panels.
+     */
+    public int getBorderColor() {
+        return mBorderColor;
+    }
+
+    /**
+     * Get the current color this view is showing.
+     *
+     * @return the current color.
+     */
+    public int getColor() {
+        return Color.HSVToColor(mAlpha, new float[] {
+                mHue, mSat, mVal
+        });
+    }
+
+    /**
+     * Set the color the view should show.
+     *
+     * @param color The color that should be selected.
+     */
+    public void setColor(int color) {
+        setColor(color, false);
+    }
+
+    /**
+     * Set the color this view should show.
+     *
+     * @param color The color that should be selected.
+     * @param callback If you want to get a callback to your
+     *            OnColorChangedListener.
+     */
+    public void setColor(int color, boolean callback) {
+        int alpha = Color.alpha(color);
+        int red = Color.red(color);
+        int blue = Color.blue(color);
+        int green = Color.green(color);
+        float[] hsv = new float[3];
+
+        Color.RGBToHSV(red, green, blue, hsv);
+        mAlpha = alpha;
+        mHue = hsv[0];
+        mSat = hsv[1];
+        mVal = hsv[2];
+
+        if (callback && mListener != null) {
+            mListener.onColorChanged(Color.HSVToColor(mAlpha, new float[] {
+                    mHue, mSat, mVal
+            }));
+        }
+        invalidate();
+    }
+
+    /**
+     * Get the drawing offset of the color picker view. The drawing offset is
+     * the distance from the side of a panel to the side of the view minus the
+     * padding. Useful if you want to have your own panel below showing the
+     * currently selected color and want to align it perfectly.
+     *
+     * @return The offset in pixels.
+     */
+    public float getDrawingOffset() {
+        return mDrawingOffset;
+    }
+
+    /**
+     * Set if the user is allowed to adjust the alpha panel. Default is false.
+     * If it is set to false no alpha will be set.
+     *
+     * @param visible
+     */
+    public void setAlphaSliderVisible(boolean visible) {
+        if (mShowAlphaPanel != visible) {
+            mShowAlphaPanel = visible;
+
+            /*
+             * Reset all shader to force a recreation. Otherwise they will not
+             * look right after the size of the view has changed.
+             */
+            mValShader = null;
+            mSatShader = null;
+            mHueShader = null;
+            mAlphaShader = null;
+            requestLayout();
+        }
+
+    }
+
+    public boolean isAlphaSliderVisible() {
+        return mShowAlphaPanel;
+    }
+
+    public void setSliderTrackerColor(int color) {
+        mSliderTrackerColor = color;
+        mHueTrackerPaint.setColor(mSliderTrackerColor);
+        invalidate();
+    }
+
+    public int getSliderTrackerColor() {
+        return mSliderTrackerColor;
+    }
+
+    /**
+     * Set the text that should be shown in the alpha slider. Set to null to
+     * disable text.
+     *
+     * @param res string resource id.
+     */
+    public void setAlphaSliderText(int res) {
+        String text = getContext().getString(res);
+        setAlphaSliderText(text);
+    }
+
+    /**
+     * Set the text that should be shown in the alpha slider. Set to null to
+     * disable text.
+     *
+     * @param text Text that should be shown.
+     */
+    public void setAlphaSliderText(String text) {
+        mAlphaSliderText = text;
+        invalidate();
+    }
+
+    /**
+     * Get the current value of the text that will be shown in the alpha slider.
+     *
+     * @return
+     */
+    public String getAlphaSliderText() {
+        return mAlphaSliderText;
+    }
+}