Android Open Source - L-Switch-backport Switch

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From Project

Back to project page L-Switch-backport.

License

The source code is released under:

Apache License

Java Source Code

package me.yugy.github.lswitchbackport.library;
//ww  w  .j ava2 s .  co  m
import android.annotation.SuppressLint;
import android.content.Context;
import android.content.res.ColorStateList;
import android.content.res.Resources;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.Typeface;
import android.graphics.drawable.AnimationDrawable;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.StateListDrawable;
import android.os.Build;
import android.os.Handler;
import android.os.Message;
import android.text.Layout;
import android.text.StaticLayout;
import android.text.TextPaint;
import android.text.TextUtils;
import android.util.AttributeSet;
import android.view.Gravity;
import android.view.MotionEvent;
import android.view.VelocityTracker;
import android.view.ViewConfiguration;
import android.widget.CompoundButton;


/**
 * Created by yugy on 2014/7/16.
 */
public class Switch extends CompoundButton {
    private static final int TOUCH_MODE_IDLE = 0;
    private static final int TOUCH_MODE_DOWN = 1;
    private static final int TOUCH_MODE_DRAGGING = 2;

    private static final int MESSAGE_ANIMATE_TO_ON = 0;
    private static final int MESSAGE_ANIMATE_TO_OFF = 1;

    private Drawable mThumbDrawable;
    private Drawable mTrackDrawable;
    private final int mSwitchMinWidth;
    private final int mSwitchPadding;

    private int mTouchMode;
    private final int mTouchSlop;
    private float mTouchX;
    private float mTouchY;
    private final VelocityTracker mVelocityTracker = VelocityTracker.obtain();
    private final int mMinFlingVelocity;

    private float mThumbPosition;
    private int mSwitchWidth;
    private int mSwitchHeight;
    private int mThumbWidth; // Does not include padding

    private int mThumbAnimateOffset;

    private int mSwitchLeft;
    private int mSwitchTop;
    private int mSwitchRight;
    private int mSwitchBottom;

    private final Rect mTempRect = new Rect();
    private Handler mHandler;

    private static final int[] CHECKED_STATE_SET = { android.R.attr.state_checked };

    /**
     * Construct a new Switch with default styling.
     *
     * @param context The Context that will determine this widget's theming.
     */
    public Switch(Context context) {
        this(context, null);
    }

    /**
     * Construct a new Switch with default styling, overriding specific style
     * attributes as requested.
     *
     * @param context The Context that will determine this widget's theming.
     * @param attrs Specification of attributes that should deviate from default styling.
     */
    public Switch(Context context, AttributeSet attrs) {
        this(context, attrs, R.attr.switchStyle);
    }

    /**
     * Construct a new Switch with a default style determined by the given theme attribute,
     * overriding specific style attributes as requested.
     *
     * @param context The Context that will determine this widget's theming.
     * @param attrs Specification of attributes that should deviate from the default styling.
     * @param defStyle An attribute ID within the active theme containing a reference to the
     *            default style for this widget. e.g. android.R.attr.switchStyle.
     */
    public Switch(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);

        final TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.Switch, defStyle, 0);

        mThumbDrawable = a.getDrawable(R.styleable.Switch_thumb);
        mTrackDrawable = a.getDrawable(R.styleable.Switch_track);
        mSwitchMinWidth = a.getDimensionPixelSize(R.styleable.Switch_switchMinWidth, 48);
        mSwitchPadding = a.getDimensionPixelSize(R.styleable.Switch_switchPadding, 16);
        mThumbWidth = a.getDimensionPixelSize(R.styleable.Switch_thumbWidth, 28);
        mThumbAnimateOffset = a.getDimensionPixelSize(R.styleable.Switch_thumbAnimateOffset, 4);

        a.recycle();


        if(mThumbDrawable == null){
            mThumbDrawable = context.getResources().getDrawable(R.drawable.switch_inner);
        }
        if(mTrackDrawable == null){
            mTrackDrawable = context.getResources().getDrawable(R.drawable.switch_track_mtrl_alpha);
        }

        final ViewConfiguration config = ViewConfiguration.get(context);
        mTouchSlop = config.getScaledTouchSlop();
        mMinFlingVelocity = config.getScaledMinimumFlingVelocity();

        // Refresh display with current params
        refreshDrawableState();
        setChecked(isChecked());

        mHandler = new Handler(new Handler.Callback() {
            @Override
            public boolean handleMessage(Message msg) {
                switch (msg.what){
                    case MESSAGE_ANIMATE_TO_OFF:
                        mThumbPosition -= mThumbAnimateOffset;
                        checkThumbPosition();
                        invalidate();
                        return true;
                    case MESSAGE_ANIMATE_TO_ON:
                        mThumbPosition += mThumbAnimateOffset;
                        checkThumbPosition();
                        invalidate();
                        return true;
                    default:
                        return false;
                }
            }
        });
    }

    private void checkThumbPosition(){
        if(mThumbPosition < 0){
            mThumbPosition = 0;
        }else if(mThumbPosition > getThumbScrollRange()){
            mThumbPosition = getThumbScrollRange();
        }
    }

    @Override
    @SuppressLint("NewApi")
    public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        mTrackDrawable.getPadding(mTempRect);
        final int switchWidth = Math.max(mSwitchMinWidth, 2 * mThumbWidth + mTempRect.left + mTempRect.right);
        final int switchHeight = mThumbDrawable.getIntrinsicHeight();

        mSwitchWidth = mSwitchMinWidth;
        mSwitchHeight = switchHeight;

        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        final int measuredHeight = getMeasuredHeight();
        if (measuredHeight < switchHeight) {
            if (Build.VERSION.SDK_INT < Build.VERSION_CODES.HONEYCOMB) {
                setMeasuredDimension(getMeasuredWidth(), switchHeight);
            }
            else {
                setMeasuredDimension(getMeasuredWidthAndState(), switchHeight);
            }
        }
    }

    /**
     * @return true if (x, y) is within the target area of the switch thumb
     */
    private boolean hitThumb(float x, float y) {
        mThumbDrawable.getPadding(mTempRect);
        final int thumbTop = mSwitchTop - mTouchSlop;
        final int thumbLeft = mSwitchLeft + (int) (mThumbPosition + 0.5f) - mTouchSlop;
        final int thumbRight = thumbLeft + mThumbWidth + mTempRect.left + mTempRect.right + mTouchSlop;
        final int thumbBottom = mSwitchBottom + mTouchSlop;
        return x > thumbLeft && x < thumbRight && y > thumbTop && y < thumbBottom;
    }

    @SuppressLint("NewApi")
    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        mVelocityTracker.addMovement(ev);

        final int action;
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.FROYO)
            action = ev.getAction();
        else
            action = ev.getActionMasked();

        switch (action) {
            case MotionEvent.ACTION_DOWN: {
                final float x = ev.getX();
                final float y = ev.getY();
                if (isEnabled() && hitThumb(x, y)) {
                    mTouchMode = TOUCH_MODE_DOWN;
                    mTouchX = x;
                    mTouchY = y;
                }
                break;
            }

            case MotionEvent.ACTION_MOVE: {
                switch (mTouchMode) {
                    case TOUCH_MODE_IDLE:
                        // Didn't target the thumb, treat normally.
                        break;

                    case TOUCH_MODE_DOWN: {
                        final float x = ev.getX();
                        final float y = ev.getY();
                        if (Math.abs(x - mTouchX) > mTouchSlop || Math.abs(y - mTouchY) > mTouchSlop) {
                            mTouchMode = TOUCH_MODE_DRAGGING;
                            getParent().requestDisallowInterceptTouchEvent(true);
                            mTouchX = x;
                            mTouchY = y;
                            return true;
                        }
                        break;
                    }

                    case TOUCH_MODE_DRAGGING: {
                        final float x = ev.getX();
                        final float dx = x - mTouchX;
                        final float newPos = Math.max(0, Math.min(mThumbPosition + dx, getThumbScrollRange()));
                        if (newPos != mThumbPosition) {
                            mThumbPosition = newPos;
                            mTouchX = x;
                            invalidate();
                        }
                        return true;
                    }
                }
                break;
            }

            case MotionEvent.ACTION_UP:
            case MotionEvent.ACTION_CANCEL: {
                if (mTouchMode == TOUCH_MODE_DRAGGING) {
                    stopDrag(ev);
                    return true;
                }
                mTouchMode = TOUCH_MODE_IDLE;
                mVelocityTracker.clear();
                break;
            }
        }

        return super.onTouchEvent(ev);
    }

    private void cancelSuperTouch(MotionEvent ev) {
        final MotionEvent cancel = MotionEvent.obtain(ev);
        cancel.setAction(MotionEvent.ACTION_CANCEL);
        super.onTouchEvent(cancel);
        cancel.recycle();
    }

    /**
     * Called from onTouchEvent to end a drag operation.
     *
     * @param ev Event that triggered the end of drag mode - ACTION_UP or ACTION_CANCEL
     */
    private void stopDrag(MotionEvent ev) {
        mTouchMode = TOUCH_MODE_IDLE;
        // Up and not canceled, also checks the switch has not been disabled during the drag
        final boolean commitChange = ev.getAction() == MotionEvent.ACTION_UP && isEnabled();

        cancelSuperTouch(ev);

        if (commitChange) {
            boolean newState;
            mVelocityTracker.computeCurrentVelocity(1000);
            final float xvel = mVelocityTracker.getXVelocity();
            if (Math.abs(xvel) > mMinFlingVelocity) {
                newState = xvel > 0;
            } else {
                newState = getTargetCheckedState();
            }
            animateThumbToCheckedState(newState);
        } else {
            animateThumbToCheckedState(isChecked());
        }
    }

    private void animateThumbToCheckedState(boolean newCheckedState) {
        // TODO animate!
        setChecked(newCheckedState);
    }

    private boolean getTargetCheckedState() {
        return mThumbPosition >= getThumbScrollRange() / 2;
    }

    @Override
    public void setChecked(boolean checked) {
        super.setChecked(checked);
//        mThumbPosition = checked ? getThumbScrollRange() : 0;
        invalidate();
    }

    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        super.onLayout(changed, left, top, right, bottom);

        mThumbPosition = isChecked() ? getThumbScrollRange() : 0;

        final int switchRight = getWidth() - getPaddingRight();
        final int switchLeft = switchRight - mSwitchWidth;
        int switchTop = 0;
        int switchBottom = 0;
        switch (getGravity() & Gravity.VERTICAL_GRAVITY_MASK) {
            case Gravity.TOP:
                switchTop = getPaddingTop();
                switchBottom = switchTop + mSwitchHeight;
                break;
            case Gravity.CENTER_VERTICAL:
                switchTop = (getPaddingTop() + getHeight() - getPaddingBottom()) / 2 - mSwitchHeight / 2;
                switchBottom = switchTop + mSwitchHeight;
                break;
            case Gravity.BOTTOM:
                switchBottom = getHeight() - getPaddingBottom();
                switchTop = switchBottom - mSwitchHeight;
                break;
        }

        mSwitchLeft = switchLeft;
        mSwitchTop = switchTop;
        mSwitchBottom = switchBottom;
        mSwitchRight = switchRight;
    }

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

        // Draw the switch
        final int switchLeft = mSwitchLeft;
        final int switchTop = mSwitchTop;
        final int switchRight = mSwitchRight;
        final int switchBottom = mSwitchBottom;

        mTrackDrawable.setBounds(switchLeft, switchTop, switchRight, switchBottom);
        mTrackDrawable.draw(canvas);

        canvas.save();

        mTrackDrawable.getPadding(mTempRect);
        final int switchInnerLeft = switchLeft + mTempRect.left;
        final int switchInnerRight = switchRight - mTempRect.right;
        canvas.clipRect(switchInnerLeft, switchTop, switchInnerRight, switchBottom);

        mThumbDrawable.getPadding(mTempRect);
        final int thumbPos = (int) (mThumbPosition + 0.5f);
        final int thumbLeft = switchInnerLeft - mTempRect.left + thumbPos;
        final int thumbRight = switchInnerLeft + thumbPos + mThumbWidth + mTempRect.right;

        mThumbDrawable.setBounds(thumbLeft, switchTop, thumbRight, switchBottom);
        mThumbDrawable.draw(canvas);

        canvas.restore();

        if(mTouchMode == TOUCH_MODE_IDLE){
            if(mThumbPosition != 0 || mThumbPosition != getThumbScrollRange()){
                if(isChecked()){
                    mHandler.sendEmptyMessageDelayed(MESSAGE_ANIMATE_TO_ON, 12);
                }else{
                    mHandler.sendEmptyMessageDelayed(MESSAGE_ANIMATE_TO_OFF, 12);
                }
            }
        }
    }

    @Override
    public int getCompoundPaddingRight() {
        int padding = super.getCompoundPaddingRight() + mSwitchWidth;
        if (!TextUtils.isEmpty(getText())) {
            padding += mSwitchPadding;
        }
        return padding;
    }

    private int getThumbScrollRange() {
        if (mTrackDrawable == null) {
            return 0;
        }
        mTrackDrawable.getPadding(mTempRect);
        return mSwitchWidth - mThumbWidth - mTempRect.left - mTempRect.right;
    }

    @Override
    protected int[] onCreateDrawableState(int extraSpace) {
        final int[] drawableState = super.onCreateDrawableState(extraSpace + 1);
        if (isChecked()) {
            mergeDrawableStates(drawableState, CHECKED_STATE_SET);
        }
        return drawableState;
    }

    @Override
    protected void drawableStateChanged() {
        super.drawableStateChanged();

        final int[] myDrawableState = getDrawableState();

        // Set the state of the Drawable
        // Drawable may be null when checked state is set from XML, from super constructor
        if (mThumbDrawable != null) mThumbDrawable.setState(myDrawableState);
        if (mTrackDrawable != null) mTrackDrawable.setState(myDrawableState);

        invalidate();
    }

    @Override
    protected boolean verifyDrawable(Drawable who) {
        return super.verifyDrawable(who) || who == mThumbDrawable || who == mTrackDrawable;
    }

    // XXX Was on the Android source, but had to comment it out (doesn't exist in 2.1). -- BoD
    // @Override
    // public void jumpDrawablesToCurrentState() {
    //     super.jumpDrawablesToCurrentState();
    //     mThumbDrawable.jumpToCurrentState();
    //     mTrackDrawable.jumpToCurrentState();
    // }
}

Java Source Code List

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