LineColorPicker.java

package uz.shift.colorpicker;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Paint.Style;
import android.graphics.Rect;
import android.os.Parcel;
import android.os.Parcelable;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;

import org.solovyev.android.calculator.R;


public class LineColorPicker extends View {

    public static final int HORIZONTAL = 0;
    public static final int VERTICAL = 1;

    int[] colors = isInEditMode() ? Palette.DEFAULT : new int[1];
    // indicate if nothing selected
    boolean isColorSelected = false;
    private Paint paint;
    private Rect rect = new Rect();
    private int selectedColor = colors[0];
    private OnColorChangedListener onColorChanged;
    private int cellSize;
    private int mOrientation = HORIZONTAL;
    private boolean isClick = false;
    private int screenW;
    private int screenH;

    public LineColorPicker(Context context, AttributeSet attrs) {
        super(context, attrs);

        paint = new Paint();
        paint.setStyle(Style.FILL);

        final TypedArray a = context.getTheme().obtainStyledAttributes(attrs, R.styleable.LineColorPicker, 0, 0);

        try {
            mOrientation = a.getInteger(R.styleable.LineColorPicker_lcp_orientation, HORIZONTAL);

            if (!isInEditMode()) {
                final int colorsArrayResId = a.getResourceId(R.styleable.LineColorPicker_lcp_colors, -1);

                if (colorsArrayResId > 0) {
                    final int[] colors = context.getResources().getIntArray(colorsArrayResId);
                    setColors(colors);
                }
            }

            final int selected = a.getInteger(R.styleable.LineColorPicker_lcp_selectedColorIndex, -1);

            if (selected != -1) {
                final int[] currentColors = getColors();

                final int currentColorsLength = currentColors != null ? currentColors.length : 0;

                if (selected < currentColorsLength) {
                    setSelectedColorPosition(selected);
                }
            }
        } finally {
            a.recycle();
        }
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        if (mOrientation == HORIZONTAL) {
            drawHorizontalPicker(canvas);
        } else {
            drawVerticalPicker(canvas);
        }

    }

    private void drawVerticalPicker(Canvas canvas) {
        rect.left = 0;
        rect.top = 0;
        rect.right = getWidth();
        rect.bottom = 0;

        // 8%
        int margin = Math.round(getWidth() * 0.08f);

        for (int i = 0; i < colors.length; i++) {

            paint.setColor(colors[i]);

            rect.top = rect.bottom;
            rect.bottom += cellSize;

            if (isColorSelected && colors[i] == selectedColor) {
                rect.left = 0;
                rect.right = getWidth();
            } else {
                rect.left = margin;
                rect.right = getWidth() - margin;
            }

            canvas.drawRect(rect, paint);
        }

    }

    private void drawHorizontalPicker(Canvas canvas) {
        rect.left = 0;
        rect.top = 0;
        rect.right = 0;
        rect.bottom = getHeight();

        // 8%
        int margin = Math.round(getHeight() * 0.08f);

        for (int i = 0; i < colors.length; i++) {

            paint.setColor(colors[i]);

            rect.left = rect.right;
            rect.right += cellSize;

            if (isColorSelected && colors[i] == selectedColor) {
                rect.top = 0;
                rect.bottom = getHeight();
            } else {
                rect.top = margin;
                rect.bottom = getHeight() - margin;
            }

            canvas.drawRect(rect, paint);
        }
    }

    private void onColorChanged(int color) {
        if (onColorChanged != null) {
            onColorChanged.onColorChanged(color);
        }
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {

        int actionId = event.getAction();

        int newColor;

        switch (actionId) {
            case MotionEvent.ACTION_DOWN:
                isClick = true;
                break;
            case MotionEvent.ACTION_UP:
                newColor = getColorAtXY(event.getX(), event.getY());

                setSelectedColor(newColor);

                if (isClick) {
                    performClick();
                }

                break;

            case MotionEvent.ACTION_MOVE:
                newColor = getColorAtXY(event.getX(), event.getY());

                setSelectedColor(newColor);

                break;
            case MotionEvent.ACTION_CANCEL:
                isClick = false;
                break;

            case MotionEvent.ACTION_OUTSIDE:
                isClick = false;
                break;

            default:
                break;
        }

        return true;
    }

    /**
     * Return color at x,y coordinate of view.
     */
    private int getColorAtXY(float x, float y) {

        // FIXME: colors.length == 0 -> devision by ZERO.s

        if (mOrientation == HORIZONTAL) {
            int left = 0;
            int right = 0;

            for (int i = 0; i < colors.length; i++) {
                left = right;
                right += cellSize;

                if (left <= x && right >= x) {
                    return colors[i];
                }
            }

        } else {
            int top = 0;
            int bottom = 0;

            for (int i = 0; i < colors.length; i++) {
                top = bottom;
                bottom += cellSize;

                if (y >= top && y <= bottom) {
                    return colors[i];
                }
            }
        }

        return selectedColor;
    }

    @Override
    protected Parcelable onSaveInstanceState() {
        // begin boilerplate code that allows parent classes to save state
        Parcelable superState = super.onSaveInstanceState();

        SavedState ss = new SavedState(superState);
        // end

        ss.selectedColor = this.selectedColor;
        ss.isColorSelected = this.isColorSelected;

        return ss;
    }

    @Override
    protected void onRestoreInstanceState(Parcelable state) {
        // begin boilerplate code so parent classes can restore state
        if (!(state instanceof SavedState)) {
            super.onRestoreInstanceState(state);
            return;
        }

        SavedState ss = (SavedState) state;
        super.onRestoreInstanceState(ss.getSuperState());
        // end

        this.selectedColor = ss.selectedColor;
        this.isColorSelected = ss.isColorSelected;
    }

    @Override
    public boolean performClick() {
        return super.performClick();
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {

        screenW = w;
        screenH = h;

        recalcCellSize();

        super.onSizeChanged(w, h, oldw, oldh);
    }

    /**
     * Return currently selected color.
     */
    public int getColor() {
        return selectedColor;
    }

    // @Override
    // protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    // int parentWidth = MeasureSpec.getSize(widthMeasureSpec);
    // int parentHeight = MeasureSpec.getSize(heightMeasureSpec);
    // this.setMeasuredDimension(parentWidth, parentHeight);
    // super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    // }

    /**
     * Set selected color as color value from palette.
     */
    public void setSelectedColor(int color) {

        // not from current palette
        if (!containsColor(colors, color)) {
            return;
        }

        // do we need to re-draw view?
        if (!isColorSelected || selectedColor != color) {
            this.selectedColor = color;

            isColorSelected = true;

            invalidate();

            onColorChanged(color);
        }
    }

    /**
     * Set selected color as index from palete
     */
    public void setSelectedColorPosition(int position) {
        setSelectedColor(colors[position]);
    }

    private int recalcCellSize() {

        if (mOrientation == HORIZONTAL) {
            cellSize = Math.round(screenW / (colors.length * 1f));
        } else {
            cellSize = Math.round(screenH / (colors.length * 1f));
        }

        return cellSize;
    }

    /**
     * Return current picker palete
     */
    public int[] getColors() {
        return colors;
    }

    /**
     * Set picker palette
     */
    public void setColors(int[] colors) {
        // TODO: selected color can be NOT in set of colors
        // FIXME: colors can be null
        this.colors = colors;

        if (!containsColor(colors, selectedColor)) {
            selectedColor = colors[0];
        }

        recalcCellSize();

        invalidate();
    }

    /**
     * Return true if palette contains this color
     */
    private boolean containsColor(int[] colors, int c) {
        for (int i = 0; i < colors.length; i++) {
            if (colors[i] == c)
                return true;

        }

        return false;
    }

    /**
     * Set onColorChanged listener
     *
     * @param l
     */
    public void setOnColorChangedListener(OnColorChangedListener l) {
        this.onColorChanged = l;
    }

    static class SavedState extends BaseSavedState {
        // required field that makes Parcelables from a Parcel
        public static final Parcelable.Creator<SavedState> CREATOR = new Parcelable.Creator<SavedState>() {
            public SavedState createFromParcel(Parcel in) {
                return new SavedState(in);
            }

            public SavedState[] newArray(int size) {
                return new SavedState[size];
            }
        };
        int selectedColor;
        boolean isColorSelected;

        SavedState(Parcelable superState) {
            super(superState);
        }

        private SavedState(Parcel in) {
            super(in);
            this.selectedColor = in.readInt();
            this.isColorSelected = in.readInt() == 1;
        }

        @Override
        public void writeToParcel(Parcel out, int flags) {
            super.writeToParcel(out, flags);
            out.writeInt(this.selectedColor);
            out.writeInt(this.isColorSelected ? 1 : 0);
        }
    }
}