FloatingTextView.java

package com.ufreedom.uikit;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PathMeasure;
import android.graphics.Rect;
import android.os.Build;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewTreeObserver;
import android.widget.FrameLayout;
import android.widget.TextView;

/**
 * UFreedom
 */
public class FloatingTextView extends TextView {

    private static final String TAG = "FloatingTextView";
    private static final int PATH_WIDTH = 2;

    private FloatingText.FloatingTextBuilder floatingTextBuilder;
    private Paint mTextPaint;

    private Paint mPathPaint;
    private PathMeasure mPathMeasure;
    private View mAttachedView;
    private boolean isMeasured;
    private boolean positionSet;


    public FloatingTextView(Context context) {
        this(context, null);
    }

    public FloatingTextView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }


    public FloatingTextView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);

        mTextPaint = new Paint();
        mTextPaint.setAntiAlias(true);
        mTextPaint.setTextAlign(Paint.Align.CENTER);
        mTextPaint.setStyle(Paint.Style.FILL);
        mTextPaint.setTextSize(100);
        mTextPaint.setColor(Color.RED);

        mPathPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        mPathPaint.setStyle(Paint.Style.STROKE);
        mPathPaint.setStrokeWidth(PATH_WIDTH);
        mPathPaint.setColor(Color.RED);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {


        if (floatingTextBuilder == null) {
            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
            return;
        }

        int widthMode = MeasureSpec.getMode(widthMeasureSpec);
        int heightMode = MeasureSpec.getMode(heightMeasureSpec);
        int widthSize = MeasureSpec.getSize(widthMeasureSpec);
        int heightSize = MeasureSpec.getSize(heightMeasureSpec);

        int widthPaddingOffset = getPaddingLeft() + getPaddingRight();
        if (widthMode == MeasureSpec.AT_MOST && heightMode == MeasureSpec.AT_MOST) {
            float maxWidth = getDesireWidth(mTextPaint);
            Paint.FontMetricsInt fmi = mTextPaint.getFontMetricsInt();
            setMeasuredDimension((int) maxWidth + widthPaddingOffset, fmi.bottom - fmi.top);
        } else if (widthMode == MeasureSpec.AT_MOST) {
            float maxWidth = getDesireWidth(mTextPaint);
            setMeasuredDimension((int) maxWidth + widthPaddingOffset, heightSize);
        } else if (heightMode == MeasureSpec.AT_MOST) {
            Paint.FontMetricsInt fmi = mTextPaint.getFontMetricsInt();
            setMeasuredDimension(widthSize + widthPaddingOffset, fmi.bottom - fmi.top);
        } else {
            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        }

        fixPosition();
        isMeasured = true;
    }


    private float getDesireWidth(Paint mTextPaint) {
        return mTextPaint.measureText(floatingTextBuilder.getTextContent());
    }


    public void setFloatingTextBuilder(FloatingText.FloatingTextBuilder floatingTextBuilder) {
        this.floatingTextBuilder = floatingTextBuilder;
        initTextStyle();
    }


    public void flyText(View view) {
        mAttachedView = view;
        Log.i(TAG, "flyText: called");

        if(isMeasured){
            fixPosition();
        } else {

            // wait on measure
            getViewTreeObserver()
                    .addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
                        @Override
                        public void onGlobalLayout() {
                            Log.i(TAG, "onGlobalLayout: called");

                            if (Build.VERSION.SDK_INT < 16) {
                                FloatingTextView.this.getViewTreeObserver().removeGlobalOnLayoutListener(this);
                            } else {
                                FloatingTextView.this.getViewTreeObserver().removeOnGlobalLayoutListener(this);
                            }

                            fixPosition();
                        }
                    });
        }
        
        FloatingPathEffect floatingPathEffect = floatingTextBuilder.getFloatingPathEffect();
        if (floatingPathEffect != null) {
            FloatingPath floatingPath = floatingPathEffect.getFloatingPath(FloatingTextView.this);
            mPathMeasure = floatingPath.getPathMeasure();
        }

        FloatingAnimator floatingAnimator = floatingTextBuilder.getFloatingAnimator();
        floatingAnimator.applyFloatingAnimation(FloatingTextView.this);
    }

    private void fixPosition() {
        if(mAttachedView == null)
            return;

        if(!positionSet) {
            Rect rect = new Rect();
            mAttachedView.getGlobalVisibleRect(rect);
            int[] location = new int[2];
            ((ViewGroup) getParent()).getLocationOnScreen(location);
            rect.offset(-location[0], -location[1]);

            int topMargin = rect.top + ((mAttachedView.getHeight() - getMeasuredHeight()) / 2) + floatingTextBuilder.getOffsetY();
            int leftMargin = rect.left + ((mAttachedView.getWidth() - getMeasuredWidth()) / 2) + floatingTextBuilder.getOffsetX();

            FrameLayout.LayoutParams lp = ((FrameLayout.LayoutParams) getLayoutParams());
            lp.topMargin = topMargin;
            lp.leftMargin = leftMargin;
            setLayoutParams(lp);

            Log.i(TAG, "flyText: width " + mAttachedView.getWidth() + " getMeasuredWidth: " + getMeasuredWidth() + " x: " + leftMargin);
            Log.i(TAG, "flyText: height " + mAttachedView.getHeight() + " getMeasuredHeight: " + getMeasuredHeight() + " y: " + topMargin);
        }
        positionSet = true;
    }

    private void initTextStyle() {
        mTextPaint.setTextSize(floatingTextBuilder.getTextSize());
        mTextPaint.setColor(floatingTextBuilder.getTextColor());
    }


    public View getAttachedView() {
        return mAttachedView;
    }

    public PathMeasure getPathMeasure() {
        return mPathMeasure;
    }

    public void dettachFromWindow() {
        ViewGroup viewParent = (ViewGroup) getParent();
        viewParent.removeView(this);
    }

    @Override
    public void draw(Canvas canvas) {
        if (!isMeasured || !positionSet)
            return;

        Log.i(TAG, "draw: isMeasured:" + isMeasured + " positionSet:" + positionSet);
        super.draw(canvas);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        if (!isMeasured || !positionSet)
            return;

        super.onDraw(canvas);
        if (floatingTextBuilder == null || mAttachedView == null) {
            return;
        }

        float x = (float) (getWidth() / 2.0);
        float y = (float) (getHeight() / 2.0);
        Paint.FontMetricsInt fmi = mTextPaint.getFontMetricsInt();
        float baseline = (float) (y - (fmi.bottom / 2.0 + fmi.top / 2.0));
        canvas.drawText(floatingTextBuilder.getTextContent(), x, baseline, mTextPaint);
    }
}