Java tutorial
/* * Firetweet - Twitter client for Android * * Copyright (C) 2012-2014 Mariotaku Lee <mariotaku.lee@gmail.com> * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ package org.getlantern.firetweet.view; import android.annotation.TargetApi; import android.content.Context; import android.content.res.TypedArray; import android.graphics.Bitmap; import android.graphics.Bitmap.Config; import android.graphics.BitmapShader; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.ColorFilter; import android.graphics.Matrix; import android.graphics.Matrix.ScaleToFit; import android.graphics.Paint; import android.graphics.PorterDuff.Mode; import android.graphics.PorterDuffXfermode; import android.graphics.RectF; import android.graphics.Shader; import android.graphics.SweepGradient; import android.graphics.drawable.BitmapDrawable; import android.graphics.drawable.ColorDrawable; import android.graphics.drawable.Drawable; import android.graphics.drawable.StateListDrawable; import android.os.Build; import android.support.annotation.IntDef; import android.support.annotation.NonNull; import android.support.v4.view.ViewCompat; import android.util.AttributeSet; import android.view.View; import android.widget.ImageView; import org.getlantern.firetweet.R; import org.getlantern.firetweet.util.accessor.ViewAccessor; import org.getlantern.firetweet.util.accessor.ViewAccessor.OutlineCompat; import org.getlantern.firetweet.util.accessor.ViewAccessor.ViewOutlineProviderCompat; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; /** * An ImageView class with a circle mask so that all images are drawn in a * circle instead of a square. */ public class ShapedImageView extends ImageView { @ShapeStyle public static final int SHAPE_CIRCLE = 0x1; @ShapeStyle public static final int SHAPE_RECTANGLE = 0x2; private static final int SHADOW_START_COLOR = 0x37000000; private static final boolean USE_OUTLINE = Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP; private static final boolean OUTLINE_DRAW = false; private final Matrix mMatrix; private final RectF mSource; private final RectF mDestination; private final RectF mTempDestination; private final Paint mBitmapPaint; private final Paint mSolidColorPaint; private final Paint mBorderPaint; private final Paint mBackgroundPaint; private boolean mBorderEnabled; private Bitmap mShadowBitmap; private float mShadowRadius; private int mStyle; private float mCornerRadius, mCornerRadiusRatio; private RectF mTransitionSource, mTransitionDestination; private int mStrokeWidth, mBorderAlpha; private int[] mBorderColors; public ShapedImageView(Context context) { this(context, null, 0); } public ShapedImageView(Context context, AttributeSet attrs) { this(context, attrs, 0); } public ShapedImageView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); final TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.ShapedImageView, defStyle, 0); mMatrix = new Matrix(); mSource = new RectF(); mDestination = new RectF(); mTempDestination = new RectF(); mBitmapPaint = new Paint(Paint.ANTI_ALIAS_FLAG); mBitmapPaint.setFilterBitmap(true); mBitmapPaint.setDither(true); mSolidColorPaint = new Paint(Paint.ANTI_ALIAS_FLAG); mBorderPaint = new Paint(Paint.ANTI_ALIAS_FLAG); mBorderPaint.setStyle(Paint.Style.STROKE); mBackgroundPaint = new Paint(Paint.ANTI_ALIAS_FLAG); if (a.hasValue(R.styleable.ShapedImageView_sivBorder)) { setBorderEnabled(a.getBoolean(R.styleable.ShapedImageView_sivBorder, false)); } else if (a.hasValue(R.styleable.ShapedImageView_sivBorderColor) || a.hasValue(R.styleable.ShapedImageView_sivBorderWidth)) { setBorderEnabled(true); } setBorderColor(a.getColor(R.styleable.ShapedImageView_sivBorderColor, Color.TRANSPARENT)); setBorderWidth(a.getDimensionPixelSize(R.styleable.ShapedImageView_sivBorderWidth, 0)); @ShapeStyle final int shapeStyle = a.getInt(R.styleable.ShapedImageView_sivShape, SHAPE_RECTANGLE); setStyle(shapeStyle); setCornerRadius(a.getDimension(R.styleable.ShapedImageView_sivCornerRadius, 0)); setCornerRadiusRatio(a.getFraction(R.styleable.ShapedImageView_sivCornerRadiusRatio, 1, 1, -1)); if (USE_OUTLINE) { if (a.hasValue(R.styleable.ShapedImageView_sivElevation)) { ViewCompat.setElevation(this, a.getDimensionPixelSize(R.styleable.ShapedImageView_sivElevation, 0)); } } else { mShadowRadius = a.getDimensionPixelSize(R.styleable.ShapedImageView_sivElevation, 0); } setBackgroundColor(a.getColor(R.styleable.ShapedImageView_sivBackgroundColor, 0)); a.recycle(); if (USE_OUTLINE) { initOutlineProvider(); } } /** * Given the source bitmap and a canvas, draws the bitmap through a circular * mask. Only draws a circle with diameter equal to the destination width. * * @param bitmap The source bitmap to draw. * @param canvas The canvas to draw it on. * @param source The source bound of the bitmap. * @param dest The destination bound on the canvas. */ public void drawBitmapWithCircleOnCanvas(Bitmap bitmap, Canvas canvas, RectF source, @NonNull RectF dest) { if (bitmap == null) { if (getStyle() == SHAPE_CIRCLE) { canvas.drawCircle(dest.centerX(), dest.centerY(), Math.min(dest.width(), dest.height()) / 2f, mSolidColorPaint); } else { final float cornerRadius = getCalculatedCornerRadius(); canvas.drawRoundRect(dest, cornerRadius, cornerRadius, mSolidColorPaint); } return; } // Draw bitmap through shader first. final BitmapShader shader = new BitmapShader(bitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP); mMatrix.reset(); switch (getScaleType()) { case CENTER_CROP: { final float srcRatio = source.width() / source.height(); final float dstRatio = dest.width() / dest.height(); if (srcRatio > dstRatio) { // Source is wider than destination, fit height mTempDestination.top = dest.top; mTempDestination.bottom = dest.bottom; final float dstWidth = dest.height() * srcRatio; mTempDestination.left = dest.centerX() - dstWidth / 2; mTempDestination.right = dest.centerX() + dstWidth / 2; } else if (srcRatio < dstRatio) { mTempDestination.left = dest.left; mTempDestination.right = dest.right; final float dstHeight = dest.width() / srcRatio; mTempDestination.top = dest.centerY() - dstHeight / 2; mTempDestination.bottom = dest.centerY() + dstHeight / 2; } else { mTempDestination.set(dest); } break; } default: { mTempDestination.set(dest); break; } } // Fit bitmap to bounds. mMatrix.setRectToRect(source, mTempDestination, ScaleToFit.CENTER); shader.setLocalMatrix(mMatrix); mBitmapPaint.setShader(shader); if (mBorderEnabled) { final float inset = mBorderPaint.getStrokeWidth() / 2; if (getStyle() == SHAPE_CIRCLE) { final float circleRadius = Math.min(dest.width(), dest.height()) / 2f - inset / 2; canvas.drawCircle(dest.centerX(), dest.centerY(), circleRadius, mBitmapPaint); } else { final float cornerRadius = getCalculatedCornerRadius(); dest.inset(inset, inset); canvas.drawRoundRect(dest, cornerRadius, cornerRadius, mBitmapPaint); dest.inset(-inset, -inset); } } else { if (getStyle() == SHAPE_CIRCLE) { final float circleRadius = Math.min(dest.width(), dest.height()) / 2f; canvas.drawCircle(dest.centerX(), dest.centerY(), circleRadius, mBitmapPaint); } else { final float cornerRadius = getCalculatedCornerRadius(); canvas.drawRoundRect(dest, cornerRadius, cornerRadius, mBitmapPaint); } } } public int[] getBorderColors() { return mBorderColors; } @ShapeStyle public int getStyle() { return mStyle; } public void setStyle(@ShapeStyle final int style) { mStyle = style; } public void setBorderColor(int color) { setBorderColorsInternal(Color.alpha(color), color); } public void setBorderColors(int... colors) { setBorderColorsInternal(0xff, colors); } public void setBorderEnabled(boolean enabled) { mBorderEnabled = enabled; invalidate(); } public void setBorderWidth(int width) { mBorderPaint.setStrokeWidth(width); mStrokeWidth = width; invalidate(); } public void setCornerRadius(float radius) { mCornerRadius = radius; } public void setCornerRadiusRatio(float ratio) { mCornerRadiusRatio = ratio; } public void setTransitionDestination(RectF dstBounds) { mTransitionDestination = dstBounds; } public void setTransitionSource(RectF srcBounds) { mTransitionSource = srcBounds; } @Override protected void onDraw(@NonNull Canvas canvas) { mDestination.set(getPaddingLeft(), getPaddingTop(), getWidth() - getPaddingRight(), getHeight() - getPaddingBottom()); if (getStyle() == SHAPE_CIRCLE) { canvas.drawOval(mDestination, mBackgroundPaint); } else { final float radius = getCalculatedCornerRadius(); canvas.drawRoundRect(mDestination, radius, radius, mBackgroundPaint); } if (OUTLINE_DRAW) { super.onDraw(canvas); } else { final int contentLeft = getPaddingLeft(), contentTop = getPaddingTop(), contentRight = getWidth() - getPaddingRight(), contentBottom = getHeight() - getPaddingBottom(); final int contentWidth = contentRight - contentLeft, contentHeight = contentBottom - contentTop; final int size = Math.min(contentWidth, contentHeight); if (mShadowBitmap != null) { canvas.drawBitmap(mShadowBitmap, contentLeft + (contentWidth - size) / 2 - mShadowRadius, contentTop + (contentHeight - size) / 2 - mShadowRadius, null); } Drawable drawable = getDrawable(); BitmapDrawable bitmapDrawable = null; // support state list drawable by getting the current state if (drawable instanceof StateListDrawable) { if (drawable.getCurrent() != null) { bitmapDrawable = (BitmapDrawable) drawable.getCurrent(); } } else if (drawable instanceof BitmapDrawable) { bitmapDrawable = (BitmapDrawable) drawable; } else if (drawable instanceof ColorDrawable) { mSolidColorPaint.setColor(((ColorDrawable) drawable).getColor()); } else { mSolidColorPaint.setColor(0); } Bitmap bitmap = null; if (bitmapDrawable != null) { bitmap = bitmapDrawable.getBitmap(); } if (bitmap != null) { mSource.set(0, 0, bitmap.getWidth(), bitmap.getHeight()); } drawBitmapWithCircleOnCanvas(bitmap, canvas, mSource, mDestination); } // Then draw the border. if (mBorderEnabled) { drawBorder(canvas, mDestination); } } @Override public void setColorFilter(ColorFilter cf) { if (OUTLINE_DRAW) { super.setColorFilter(cf); return; } mBitmapPaint.setColorFilter(cf); } @Override protected void onSizeChanged(int w, int h, int oldw, int oldh) { super.onSizeChanged(w, h, oldw, oldh); } @Override protected void dispatchDraw(Canvas canvas) { super.dispatchDraw(canvas); } @Override protected void onLayout(boolean changed, int left, int top, int right, int bottom) { super.onLayout(changed, left, top, right, bottom); updateBounds(); } @Override public void setBackgroundColor(int color) { mBackgroundPaint.setColor(0xFF000000 | color); mBackgroundPaint.setAlpha(Color.alpha(color)); invalidate(); } @TargetApi(Build.VERSION_CODES.JELLY_BEAN) @Override public void setBackground(Drawable background) { } @Deprecated @Override public void setBackgroundDrawable(Drawable background) { // No-op } @Override public void setPadding(int left, int top, int right, int bottom) { super.setPadding(left, top, right, bottom); updateBounds(); } @TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR1) @Override public void setPaddingRelative(int start, int top, int end, int bottom) { super.setPaddingRelative(start, top, end, bottom); updateBounds(); } private void drawBorder(@NonNull final Canvas canvas, @NonNull final RectF dest) { if (mBorderColors == null) return; final RectF transitionSrc = mTransitionSource, transitionDst = mTransitionDestination; final float strokeWidth; if (transitionSrc != null && transitionDst != null) { final float progress = 1 - (dest.width() - transitionDst.width()) / (transitionSrc.width() - transitionDst.width()); strokeWidth = mStrokeWidth * progress; mBorderPaint.setAlpha(Math.round(mBorderAlpha * progress)); ViewCompat.setTranslationZ(this, -ViewCompat.getElevation(this) * (1 - progress)); } else { strokeWidth = mStrokeWidth; mBorderPaint.setAlpha(mBorderAlpha); ViewCompat.setTranslationZ(this, 0); } mBorderPaint.setStrokeWidth(strokeWidth); if (getStyle() == SHAPE_CIRCLE) { final float circleRadius = Math.min(dest.width(), dest.height()) / 2f - strokeWidth / 2; canvas.drawCircle(dest.centerX(), dest.centerY(), circleRadius, mBorderPaint); } else { final float radius = getCalculatedCornerRadius(); final float inset = mStrokeWidth / 2; dest.inset(inset, inset); canvas.drawRoundRect(dest, radius, radius, mBorderPaint); dest.inset(-inset, -inset); } } private float getCalculatedCornerRadius() { if (mCornerRadiusRatio > 0) { return Math.min(getWidth(), getHeight()) * mCornerRadiusRatio; } else if (mCornerRadius > 0) { return mCornerRadius; } return 0; } private void initOutlineProvider() { ViewAccessor.setClipToOutline(this, true); ViewAccessor.setOutlineProvider(this, new CircularOutlineProvider()); } private void setBorderColorsInternal(int alpha, int... colors) { mBorderAlpha = alpha; mBorderColors = colors; updateBorderShader(); invalidate(); } private void updateBorderShader() { final int[] colors = mBorderColors; if (colors == null || colors.length == 0) { mBorderAlpha = 0; return; } mDestination.set(getPaddingLeft(), getPaddingTop(), getWidth() - getPaddingRight(), getHeight() - getPaddingBottom()); final float cx = mDestination.centerX(), cy = mDestination.centerY(); final int[] sweepColors = new int[colors.length * 2]; final float[] positions = new float[colors.length * 2]; for (int i = 0, j = colors.length; i < j; i++) { sweepColors[i * 2] = sweepColors[i * 2 + 1] = colors[i]; positions[i * 2] = i == 0 ? 0 : i / (float) j; positions[i * 2 + 1] = i == j - 1 ? 1 : (i + 1) / (float) j; } final SweepGradient shader = new SweepGradient(cx, cy, sweepColors, positions); final Matrix matrix = new Matrix(); matrix.setRotate(90, cx, cy); shader.setLocalMatrix(matrix); mBorderPaint.setShader(shader); } private void updateBounds() { updateBorderShader(); updateShadowBitmap(); } private void updateShadowBitmap() { if (USE_OUTLINE) return; final int width = getWidth(), height = getHeight(); if (width <= 0 || height <= 0) return; final int contentLeft = getPaddingLeft(), contentTop = getPaddingTop(), contentRight = width - getPaddingRight(), contentBottom = height - getPaddingBottom(); final int contentWidth = contentRight - contentLeft, contentHeight = contentBottom - contentTop; final float radius = mShadowRadius, dy = radius * 1.5f / 2; final int size = Math.round(Math.min(contentWidth, contentHeight) + radius * 2); mShadowBitmap = Bitmap.createBitmap(size, Math.round(size + dy), Config.ARGB_8888); Canvas canvas = new Canvas(mShadowBitmap); final Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG); paint.setColor(0xFF000000 | mBackgroundPaint.getColor()); paint.setShadowLayer(radius, 0, radius * 1.5f / 2, SHADOW_START_COLOR); final RectF rect = new RectF(radius, radius, size - radius, size - radius); if (getStyle() == SHAPE_CIRCLE) { canvas.drawOval(rect, paint); paint.setShadowLayer(0, 0, 0, 0); paint.setXfermode(new PorterDuffXfermode(Mode.CLEAR)); canvas.drawOval(rect, paint); } else { final float cr = getCalculatedCornerRadius(); canvas.drawRoundRect(rect, cr, cr, paint); paint.setShadowLayer(0, 0, 0, 0); paint.setXfermode(new PorterDuffXfermode(Mode.CLEAR)); canvas.drawRoundRect(rect, cr, cr, paint); } invalidate(); } @IntDef({ SHAPE_CIRCLE, SHAPE_RECTANGLE }) @Retention(RetentionPolicy.SOURCE) public @interface ShapeStyle { } private static class CircularOutlineProvider extends ViewOutlineProviderCompat { @Override public void getOutline(View view, OutlineCompat outline) { final int contentLeft = view.getPaddingLeft(), contentTop = view.getPaddingTop(), contentRight = view.getWidth() - view.getPaddingRight(), contentBottom = view.getHeight() - view.getPaddingBottom(); final ShapedImageView imageView = (ShapedImageView) view; if (imageView.getStyle() == SHAPE_CIRCLE) { final int contentWidth = contentRight - contentLeft, contentHeight = contentBottom - contentTop; final int size = Math.min(contentWidth, contentHeight); outline.setOval(contentLeft + (contentWidth - size) / 2, contentTop + (contentHeight - size) / 2, contentRight - (contentWidth - size) / 2, contentBottom - (contentHeight - size) / 2); } else { final float radius = imageView.getCalculatedCornerRadius(); outline.setRoundRect(contentLeft, contentTop, contentRight, contentBottom, radius); } } } }