Java tutorial
/* * Copyright (C) 2015 The Android Open Source Project * Modified 2015 by Johan v. Forstner (modifications are marked with comments) * * 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 net.opacapp.multilinecollapsingtoolbar; import android.content.res.TypedArray; import android.graphics.Bitmap; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.Rect; import android.graphics.RectF; import android.graphics.Typeface; import android.os.Build; import android.support.v4.text.TextDirectionHeuristicsCompat; import android.support.v4.view.GravityCompat; import android.support.v4.view.ViewCompat; // BEGIN MODIFICATION: Added imports import android.text.Layout; import android.text.StaticLayout; // END MODIFICATION import android.text.TextPaint; import android.text.TextUtils; import android.view.Gravity; import android.view.View; import android.view.animation.Interpolator; final class CollapsingTextHelper { // Pre-JB-MR2 doesn't support HW accelerated canvas scaled text so we will workaround it // by using our own texture private static final boolean USE_SCALING_TEXTURE = Build.VERSION.SDK_INT < 18; private static final boolean DEBUG_DRAW = false; private static final Paint DEBUG_DRAW_PAINT; static { DEBUG_DRAW_PAINT = DEBUG_DRAW ? new Paint() : null; if (DEBUG_DRAW_PAINT != null) { DEBUG_DRAW_PAINT.setAntiAlias(true); DEBUG_DRAW_PAINT.setColor(Color.MAGENTA); } } private final View mView; private boolean mDrawTitle; private float mExpandedFraction; private final Rect mExpandedBounds; private final Rect mCollapsedBounds; private final RectF mCurrentBounds; private int mExpandedTextGravity = Gravity.CENTER_VERTICAL; private int mCollapsedTextGravity = Gravity.CENTER_VERTICAL; private float mExpandedTextSize = 15; private float mCollapsedTextSize = 15; private int mExpandedTextColor; private int mCollapsedTextColor; private float mExpandedDrawY; private float mCollapsedDrawY; private float mExpandedDrawX; private float mCollapsedDrawX; private float mCurrentDrawX; private float mCurrentDrawY; private Typeface mCollapsedTypeface; private Typeface mExpandedTypeface; private Typeface mCurrentTypeface; private CharSequence mText; private CharSequence mTextToDraw; private boolean mIsRtl; private boolean mUseTexture; private Bitmap mExpandedTitleTexture; private Paint mTexturePaint; // MODIFICATION: Removed now unused fields mTextureAscent and mTextureDescent private float mScale; private float mCurrentTextSize; private boolean mBoundsChanged; private final TextPaint mTextPaint; private Interpolator mPositionInterpolator; private Interpolator mTextSizeInterpolator; private float mCollapsedShadowRadius, mCollapsedShadowDx, mCollapsedShadowDy; private int mCollapsedShadowColor; private float mExpandedShadowRadius, mExpandedShadowDx, mExpandedShadowDy; private int mExpandedShadowColor; // BEGIN MODIFICATION: Added fields private CharSequence mTextToDrawCollapsed; private Bitmap mCollapsedTitleTexture; private Bitmap mCrossSectionTitleTexture; private StaticLayout mTextLayout; private float mCollapsedTextBlend; private float mExpandedTextBlend; private float mExpandedFirstLineDrawX; private int maxLines = 3; // END MODIFICATION public CollapsingTextHelper(View view) { mView = view; mTextPaint = new TextPaint(Paint.ANTI_ALIAS_FLAG | Paint.SUBPIXEL_TEXT_FLAG); mCollapsedBounds = new Rect(); mExpandedBounds = new Rect(); mCurrentBounds = new RectF(); } void setTextSizeInterpolator(Interpolator interpolator) { mTextSizeInterpolator = interpolator; recalculate(); } void setPositionInterpolator(Interpolator interpolator) { mPositionInterpolator = interpolator; recalculate(); } void setExpandedTextSize(float textSize) { if (mExpandedTextSize != textSize) { mExpandedTextSize = textSize; recalculate(); } } void setCollapsedTextSize(float textSize) { if (mCollapsedTextSize != textSize) { mCollapsedTextSize = textSize; recalculate(); } } void setCollapsedTextColor(int textColor) { if (mCollapsedTextColor != textColor) { mCollapsedTextColor = textColor; recalculate(); } } void setExpandedTextColor(int textColor) { if (mExpandedTextColor != textColor) { mExpandedTextColor = textColor; recalculate(); } } void setExpandedBounds(int left, int top, int right, int bottom) { if (!rectEquals(mExpandedBounds, left, top, right, bottom)) { mExpandedBounds.set(left, top, right, bottom); mBoundsChanged = true; onBoundsChanged(); } } void setCollapsedBounds(int left, int top, int right, int bottom) { if (!rectEquals(mCollapsedBounds, left, top, right, bottom)) { mCollapsedBounds.set(left, top, right, bottom); mBoundsChanged = true; onBoundsChanged(); } } void onBoundsChanged() { mDrawTitle = mCollapsedBounds.width() > 0 && mCollapsedBounds.height() > 0 && mExpandedBounds.width() > 0 && mExpandedBounds.height() > 0; } void setExpandedTextGravity(int gravity) { if (mExpandedTextGravity != gravity) { mExpandedTextGravity = gravity; recalculate(); } } int getExpandedTextGravity() { return mExpandedTextGravity; } void setCollapsedTextGravity(int gravity) { if (mCollapsedTextGravity != gravity) { mCollapsedTextGravity = gravity; recalculate(); } } int getCollapsedTextGravity() { return mCollapsedTextGravity; } void setCollapsedTextAppearance(int resId) { TypedArray a = mView.getContext().obtainStyledAttributes(resId, android.support.v7.appcompat.R.styleable.TextAppearance); if (a.hasValue(android.support.v7.appcompat.R.styleable.TextAppearance_android_textColor)) { mCollapsedTextColor = a.getColor( android.support.v7.appcompat.R.styleable.TextAppearance_android_textColor, mCollapsedTextColor); } if (a.hasValue(android.support.v7.appcompat.R.styleable.TextAppearance_android_textSize)) { mCollapsedTextSize = a.getDimensionPixelSize( android.support.v7.appcompat.R.styleable.TextAppearance_android_textSize, (int) mCollapsedTextSize); } mCollapsedShadowColor = a .getInt(android.support.v7.appcompat.R.styleable.TextAppearance_android_shadowColor, 0); mCollapsedShadowDx = a.getFloat(android.support.v7.appcompat.R.styleable.TextAppearance_android_shadowDx, 0); mCollapsedShadowDy = a.getFloat(android.support.v7.appcompat.R.styleable.TextAppearance_android_shadowDy, 0); mCollapsedShadowRadius = a .getFloat(android.support.v7.appcompat.R.styleable.TextAppearance_android_shadowRadius, 0); a.recycle(); if (Build.VERSION.SDK_INT >= 16) { mCollapsedTypeface = readFontFamilyTypeface(resId); } recalculate(); } void setExpandedTextAppearance(int resId) { TypedArray a = mView.getContext().obtainStyledAttributes(resId, android.support.v7.appcompat.R.styleable.TextAppearance); if (a.hasValue(android.support.v7.appcompat.R.styleable.TextAppearance_android_textColor)) { mExpandedTextColor = a.getColor( android.support.v7.appcompat.R.styleable.TextAppearance_android_textColor, mExpandedTextColor); } if (a.hasValue(android.support.v7.appcompat.R.styleable.TextAppearance_android_textSize)) { mExpandedTextSize = a.getDimensionPixelSize( android.support.v7.appcompat.R.styleable.TextAppearance_android_textSize, (int) mExpandedTextSize); } mExpandedShadowColor = a.getInt(android.support.v7.appcompat.R.styleable.TextAppearance_android_shadowColor, 0); mExpandedShadowDx = a.getFloat(android.support.v7.appcompat.R.styleable.TextAppearance_android_shadowDx, 0); mExpandedShadowDy = a.getFloat(android.support.v7.appcompat.R.styleable.TextAppearance_android_shadowDy, 0); mExpandedShadowRadius = a .getFloat(android.support.v7.appcompat.R.styleable.TextAppearance_android_shadowRadius, 0); a.recycle(); if (Build.VERSION.SDK_INT >= 16) { mExpandedTypeface = readFontFamilyTypeface(resId); } recalculate(); } // BEGIN MODIFICATION: getter and setter method for number of max lines void setMaxLines(int maxLines) { if (maxLines != this.maxLines) { this.maxLines = maxLines; clearTexture(); recalculate(); } } int getMaxLines() { return maxLines; } // END MODIFICATION private Typeface readFontFamilyTypeface(int resId) { final TypedArray a = mView.getContext().obtainStyledAttributes(resId, new int[] { android.R.attr.fontFamily }); try { final String family = a.getString(0); if (family != null) { return Typeface.create(family, Typeface.NORMAL); } } finally { a.recycle(); } return null; } void setCollapsedTypeface(Typeface typeface) { if (mCollapsedTypeface != typeface) { mCollapsedTypeface = typeface; recalculate(); } } void setExpandedTypeface(Typeface typeface) { if (mExpandedTypeface != typeface) { mExpandedTypeface = typeface; recalculate(); } } void setTypefaces(Typeface typeface) { mCollapsedTypeface = mExpandedTypeface = typeface; recalculate(); } Typeface getCollapsedTypeface() { return mCollapsedTypeface != null ? mCollapsedTypeface : Typeface.DEFAULT; } Typeface getExpandedTypeface() { return mExpandedTypeface != null ? mExpandedTypeface : Typeface.DEFAULT; } /** * Set the value indicating the current scroll value. This decides how much of the * background will be displayed, as well as the title metrics/positioning. * * A value of {@code 0.0} indicates that the layout is fully expanded. * A value of {@code 1.0} indicates that the layout is fully collapsed. */ void setExpansionFraction(float fraction) { fraction = MathUtils.constrain(fraction, 0f, 1f); if (fraction != mExpandedFraction) { mExpandedFraction = fraction; calculateCurrentOffsets(); } } float getExpansionFraction() { return mExpandedFraction; } float getCollapsedTextSize() { return mCollapsedTextSize; } float getExpandedTextSize() { return mExpandedTextSize; } private void calculateCurrentOffsets() { calculateOffsets(mExpandedFraction); } private void calculateOffsets(final float fraction) { interpolateBounds(fraction); mCurrentDrawX = lerp(mExpandedDrawX, mCollapsedDrawX, fraction, mPositionInterpolator); mCurrentDrawY = lerp(mExpandedDrawY, mCollapsedDrawY, fraction, mPositionInterpolator); setInterpolatedTextSize(lerp(mExpandedTextSize, mCollapsedTextSize, fraction, mTextSizeInterpolator)); // BEGIN MODIFICATION: set text blending setCollapsedTextBlend(1 - lerp(0, 1, 1 - fraction, AnimationUtils.FAST_OUT_SLOW_IN_INTERPOLATOR)); setExpandedTextBlend(lerp(1, 0, fraction, AnimationUtils.FAST_OUT_SLOW_IN_INTERPOLATOR)); // END MODIFICATION if (mCollapsedTextColor != mExpandedTextColor) { // If the collapsed and expanded text colors are different, blend them based on the // fraction mTextPaint.setColor(blendColors(mExpandedTextColor, mCollapsedTextColor, fraction)); } else { mTextPaint.setColor(mCollapsedTextColor); } mTextPaint.setShadowLayer(lerp(mExpandedShadowRadius, mCollapsedShadowRadius, fraction, null), lerp(mExpandedShadowDx, mCollapsedShadowDx, fraction, null), lerp(mExpandedShadowDy, mCollapsedShadowDy, fraction, null), blendColors(mExpandedShadowColor, mCollapsedShadowColor, fraction)); ViewCompat.postInvalidateOnAnimation(mView); } private void calculateBaseOffsets() { final float currentTextSize = mCurrentTextSize; // We then calculate the collapsed text size, using the same logic calculateUsingTextSize(mCollapsedTextSize); // BEGIN MODIFICATION: set mTextToDrawCollapsed and calculate width using it mTextToDrawCollapsed = mTextToDraw; float width = mTextToDrawCollapsed != null ? mTextPaint.measureText(mTextToDrawCollapsed, 0, mTextToDrawCollapsed.length()) : 0; // END MODIFICATION final int collapsedAbsGravity = GravityCompat.getAbsoluteGravity(mCollapsedTextGravity, mIsRtl ? ViewCompat.LAYOUT_DIRECTION_RTL : ViewCompat.LAYOUT_DIRECTION_LTR); // BEGIN MODIFICATION: calculate height and Y position using mTextLayout float textHeight = mTextLayout != null ? mTextLayout.getHeight() : 0; switch (collapsedAbsGravity & Gravity.VERTICAL_GRAVITY_MASK) { case Gravity.BOTTOM: mCollapsedDrawY = mCollapsedBounds.bottom - textHeight; break; case Gravity.TOP: mCollapsedDrawY = mCollapsedBounds.top; break; case Gravity.CENTER_VERTICAL: default: float textOffset = (textHeight / 2); mCollapsedDrawY = mCollapsedBounds.centerY() - textOffset; break; } // END MODIFICATION switch (collapsedAbsGravity & GravityCompat.RELATIVE_HORIZONTAL_GRAVITY_MASK) { case Gravity.CENTER_HORIZONTAL: mCollapsedDrawX = mCollapsedBounds.centerX() - (width / 2); break; case Gravity.RIGHT: mCollapsedDrawX = mCollapsedBounds.right - width; break; case Gravity.LEFT: default: mCollapsedDrawX = mCollapsedBounds.left; break; } calculateUsingTextSize(mExpandedTextSize); // BEGIN MODIFICATION: calculate width using mTextLayout based on first line and store that padding width = mTextLayout != null ? mTextLayout.getLineWidth(0) : 0; mExpandedFirstLineDrawX = mTextLayout != null ? mTextLayout.getLineLeft(0) : 0; // END MODIFICATION final int expandedAbsGravity = GravityCompat.getAbsoluteGravity(mExpandedTextGravity, mIsRtl ? ViewCompat.LAYOUT_DIRECTION_RTL : ViewCompat.LAYOUT_DIRECTION_LTR); // BEGIN MODIFICATION: calculate height and Y position using mTextLayout textHeight = mTextLayout != null ? mTextLayout.getHeight() : 0; switch (expandedAbsGravity & Gravity.VERTICAL_GRAVITY_MASK) { case Gravity.BOTTOM: mExpandedDrawY = mExpandedBounds.bottom - textHeight; break; case Gravity.TOP: mExpandedDrawY = mExpandedBounds.top; break; case Gravity.CENTER_VERTICAL: default: float textOffset = (textHeight / 2); mExpandedDrawY = mExpandedBounds.centerY() - textOffset; break; } // END MODIFICATION switch (expandedAbsGravity & GravityCompat.RELATIVE_HORIZONTAL_GRAVITY_MASK) { case Gravity.CENTER_HORIZONTAL: mExpandedDrawX = mExpandedBounds.centerX() - (width / 2); break; case Gravity.RIGHT: mExpandedDrawX = mExpandedBounds.right - width; break; case Gravity.LEFT: default: mExpandedDrawX = mExpandedBounds.left; break; } // The bounds have changed so we need to clear the texture clearTexture(); // Now reset the text size back to the original setInterpolatedTextSize(currentTextSize); } private void interpolateBounds(float fraction) { mCurrentBounds.left = lerp(mExpandedBounds.left, mCollapsedBounds.left, fraction, mPositionInterpolator); mCurrentBounds.top = lerp(mExpandedDrawY, mCollapsedDrawY, fraction, mPositionInterpolator); mCurrentBounds.right = lerp(mExpandedBounds.right, mCollapsedBounds.right, fraction, mPositionInterpolator); mCurrentBounds.bottom = lerp(mExpandedBounds.bottom, mCollapsedBounds.bottom, fraction, mPositionInterpolator); } public void draw(Canvas canvas) { final int saveCount = canvas.save(); if (mTextToDraw != null && mDrawTitle) { float x = mCurrentDrawX; float y = mCurrentDrawY; final boolean drawTexture = mUseTexture && mExpandedTitleTexture != null; final float ascent; // MODIFICATION: removed now unused "descent" variable declaration // Update the TextPaint to the current text size mTextPaint.setTextSize(mCurrentTextSize); // BEGIN MODIFICATION: new drawing code if (drawTexture) { ascent = 0; } else { ascent = mTextPaint.ascent() * mScale; } if (DEBUG_DRAW) { // Just a debug tool, which drawn a Magneta rect in the text bounds canvas.drawRect(mCurrentBounds.left, y, mCurrentBounds.right, y + mTextLayout.getHeight() * mScale, DEBUG_DRAW_PAINT); } if (mScale != 1f) { canvas.scale(mScale, mScale, x, y); } // Compute where to draw mTextLayout for this frame final float currentExpandedX = mCurrentDrawX + mTextLayout.getLineLeft(0) - mExpandedFirstLineDrawX * 2; if (drawTexture) { // If we should use a texture, draw it instead of text // Expanded text mTexturePaint.setAlpha((int) (mExpandedTextBlend * 255)); canvas.drawBitmap(mExpandedTitleTexture, currentExpandedX, y, mTexturePaint); // Collapsed text mTexturePaint.setAlpha((int) (mCollapsedTextBlend * 255)); canvas.drawBitmap(mCollapsedTitleTexture, x, y, mTexturePaint); // Cross-section between both texts (should stay at alpha = 255) mTexturePaint.setAlpha(255); canvas.drawBitmap(mCrossSectionTitleTexture, x, y, mTexturePaint); } else { // positon expanded text appropriately canvas.translate(currentExpandedX, y); // Expanded text mTextPaint.setAlpha((int) (mExpandedTextBlend * 255)); mTextLayout.draw(canvas); // position the overlays canvas.translate(x - currentExpandedX, 0); // Collapsed text mTextPaint.setAlpha((int) (mCollapsedTextBlend * 255)); canvas.drawText(mTextToDrawCollapsed, 0, mTextToDrawCollapsed.length(), 0, -ascent / mScale, mTextPaint); // Cross-section between both texts (should stay at alpha = 255) mTextPaint.setAlpha(255); canvas.drawText(mTextToDraw, mTextLayout.getLineStart(0), mTextLayout.getLineEnd(0), 0, -ascent / mScale, mTextPaint); } // END MODIFICATION } canvas.restoreToCount(saveCount); } private boolean calculateIsRtl(CharSequence text) { final boolean defaultIsRtl = ViewCompat.getLayoutDirection(mView) == ViewCompat.LAYOUT_DIRECTION_RTL; return (defaultIsRtl ? TextDirectionHeuristicsCompat.FIRSTSTRONG_RTL : TextDirectionHeuristicsCompat.FIRSTSTRONG_LTR).isRtl(text, 0, text.length()); } private void setInterpolatedTextSize(float textSize) { calculateUsingTextSize(textSize); // Use our texture if the scale isn't 1.0 mUseTexture = USE_SCALING_TEXTURE && mScale != 1f; if (mUseTexture) { // Make sure we have an expanded texture if needed ensureExpandedTexture(); // BEGIN MODIFICATION: added collapsed and cross section textures ensureCollapsedTexture(); ensureCrossSectionTexture(); } ViewCompat.postInvalidateOnAnimation(mView); // END MODIFICATION } // BEGIN MODIFICATION: new setCollapsedTextBlend and setExpandedTextBlend methods private void setCollapsedTextBlend(float blend) { mCollapsedTextBlend = blend; ViewCompat.postInvalidateOnAnimation(mView); } private void setExpandedTextBlend(float blend) { mExpandedTextBlend = blend; ViewCompat.postInvalidateOnAnimation(mView); } // END MODIFICATION private void calculateUsingTextSize(final float textSize) { if (mText == null) return; final float availableWidth; final float newTextSize; boolean updateDrawText = false; // BEGIN MODIFICATION: Add maxLines variable int maxLines; // END MODIFICATION if (isClose(textSize, mCollapsedTextSize)) { availableWidth = mCollapsedBounds.width(); newTextSize = mCollapsedTextSize; mScale = 1f; if (mCurrentTypeface != mCollapsedTypeface) { mCurrentTypeface = mCollapsedTypeface; updateDrawText = true; } // BEGIN MODIFICATION: Set maxLines variable maxLines = 1; // END MODIFICATION } else { availableWidth = mExpandedBounds.width(); newTextSize = mExpandedTextSize; if (mCurrentTypeface != mExpandedTypeface) { mCurrentTypeface = mExpandedTypeface; updateDrawText = true; } if (isClose(textSize, mExpandedTextSize)) { // If we're close to the expanded text size, snap to it and use a scale of 1 mScale = 1f; } else { // Else, we'll scale down from the expanded text size mScale = textSize / mExpandedTextSize; } // BEGIN MODIFICATION: Set maxLines variable maxLines = this.maxLines; // END MODIFICATION } if (availableWidth > 0) { updateDrawText = (mCurrentTextSize != newTextSize) || mBoundsChanged || updateDrawText; mCurrentTextSize = newTextSize; mBoundsChanged = false; } if (mTextToDraw == null || updateDrawText) { mTextPaint.setTextSize(mCurrentTextSize); mTextPaint.setTypeface(mCurrentTypeface); // BEGIN MODIFICATION: Text layout creation and text truncation StaticLayout layout = new StaticLayout(mText, mTextPaint, (int) availableWidth, Layout.Alignment.ALIGN_NORMAL, 1, 0, false); CharSequence truncatedText; if (layout.getLineCount() > maxLines) { int lastLine = maxLines - 1; CharSequence textBefore = lastLine > 0 ? mText.subSequence(0, layout.getLineEnd(lastLine - 1)) : ""; CharSequence lineText = mText.subSequence(layout.getLineStart(lastLine), layout.getLineEnd(lastLine)); // if last char in line is space, move it behind the ellipsis CharSequence lineEnd = ""; if (lineText.charAt(lineText.length() - 1) == ' ') { lineEnd = lineText.subSequence(lineText.length() - 1, lineText.length()); lineText = lineText.subSequence(0, lineText.length() - 1); } // insert ellipsis character lineText = TextUtils.concat(lineText, "\u2026", lineEnd); // if the text is too long, truncate it CharSequence truncatedLineText = TextUtils.ellipsize(lineText, mTextPaint, availableWidth, TextUtils.TruncateAt.END); truncatedText = TextUtils.concat(textBefore, truncatedLineText); } else { truncatedText = mText; } if (!TextUtils.equals(truncatedText, mTextToDraw)) { mTextToDraw = truncatedText; mIsRtl = calculateIsRtl(mTextToDraw); } final Layout.Alignment alignment; // Don't rectify gravity for RTL languages, Layout.Alignment does it already. switch (mExpandedTextGravity & GravityCompat.RELATIVE_HORIZONTAL_GRAVITY_MASK) { case Gravity.CENTER_HORIZONTAL: alignment = Layout.Alignment.ALIGN_CENTER; break; case Gravity.RIGHT: case Gravity.END: alignment = Layout.Alignment.ALIGN_OPPOSITE; break; case Gravity.LEFT: case Gravity.START: default: alignment = Layout.Alignment.ALIGN_NORMAL; break; } mTextLayout = new StaticLayout(mTextToDraw, mTextPaint, (int) availableWidth, alignment, 1, 0, false); // END MODIFICATION } } private void ensureExpandedTexture() { if (mExpandedTitleTexture != null || mExpandedBounds.isEmpty() || TextUtils.isEmpty(mTextToDraw)) { return; } calculateOffsets(0f); // BEGIN MODIFICATION: Calculate width and height using mTextLayout and remove // mTextureAscent and mTextureDescent assignment final int w = mTextLayout.getWidth(); final int h = mTextLayout.getHeight(); // END MODIFICATION if (w <= 0 || h <= 0) { return; // If the width or height are 0, return } mExpandedTitleTexture = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888); // BEGIN MODIFICATION: Draw text using mTextLayout Canvas c = new Canvas(mExpandedTitleTexture); mTextLayout.draw(c); // END MODIFICATION if (mTexturePaint == null) { // Make sure we have a paint mTexturePaint = new Paint(Paint.ANTI_ALIAS_FLAG | Paint.FILTER_BITMAP_FLAG); } } // BEGIN MODIFICATION: new ensureCollapsedTexture and ensureCrossSectionTexture methods private void ensureCollapsedTexture() { if (mCollapsedTitleTexture != null || mCollapsedBounds.isEmpty() || TextUtils.isEmpty(mTextToDraw)) { return; } calculateOffsets(0f); final int w = Math.round(mTextPaint.measureText(mTextToDraw, 0, mTextToDraw.length())); final int h = Math.round(mTextPaint.descent() - mTextPaint.ascent()); if (w <= 0 && h <= 0) { return; // If the width or height are 0, return } mCollapsedTitleTexture = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888); Canvas c = new Canvas(mCollapsedTitleTexture); c.drawText(mTextToDrawCollapsed, 0, mTextToDrawCollapsed.length(), 0, -mTextPaint.ascent() / mScale, mTextPaint); if (mTexturePaint == null) { // Make sure we have a paint mTexturePaint = new Paint(Paint.ANTI_ALIAS_FLAG | Paint.FILTER_BITMAP_FLAG); } } private void ensureCrossSectionTexture() { if (mCrossSectionTitleTexture != null || mCollapsedBounds.isEmpty() || TextUtils.isEmpty(mTextToDraw)) { return; } calculateOffsets(0f); final int w = Math .round(mTextPaint.measureText(mTextToDraw, mTextLayout.getLineStart(0), mTextLayout.getLineEnd(0))); final int h = Math.round(mTextPaint.descent() - mTextPaint.ascent()); if (w <= 0 && h <= 0) { return; // If the width or height are 0, return } mCrossSectionTitleTexture = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888); Canvas c = new Canvas(mCrossSectionTitleTexture); c.drawText(mTextToDraw, mTextLayout.getLineStart(0), mTextLayout.getLineEnd(0), 0, -mTextPaint.ascent() / mScale, mTextPaint); if (mTexturePaint == null) { // Make sure we have a paint mTexturePaint = new Paint(Paint.ANTI_ALIAS_FLAG | Paint.FILTER_BITMAP_FLAG); } } // END MODIFICATION public void recalculate() { if (mView.getHeight() > 0 && mView.getWidth() > 0) { // If we've already been laid out, calculate everything now otherwise we'll wait // until a layout calculateBaseOffsets(); calculateCurrentOffsets(); } } /** * Set the title to display * * @param text */ void setText(CharSequence text) { if (text == null || !text.equals(mText)) { mText = text; mTextToDraw = null; clearTexture(); recalculate(); } } CharSequence getText() { return mText; } private void clearTexture() { if (mExpandedTitleTexture != null) { mExpandedTitleTexture.recycle(); mExpandedTitleTexture = null; } // BEGIN MODIFICATION: clear other textures if (mCollapsedTitleTexture != null) { mCollapsedTitleTexture.recycle(); mCollapsedTitleTexture = null; } if (mCrossSectionTitleTexture != null) { mCrossSectionTitleTexture.recycle(); mCrossSectionTitleTexture = null; } // END MODIFICATION } /** * Returns true if {@code value} is 'close' to it's closest decimal value. Close is currently * defined as it's difference being < 0.001. */ private static boolean isClose(float value, float targetValue) { return Math.abs(value - targetValue) < 0.001f; } int getExpandedTextColor() { return mExpandedTextColor; } int getCollapsedTextColor() { return mCollapsedTextColor; } /** * Blend {@code color1} and {@code color2} using the given ratio. * * @param ratio of which to blend. 0.0 will return {@code color1}, 0.5 will give an even blend, * 1.0 will return {@code color2}. */ private static int blendColors(int color1, int color2, float ratio) { final float inverseRatio = 1f - ratio; float a = (Color.alpha(color1) * inverseRatio) + (Color.alpha(color2) * ratio); float r = (Color.red(color1) * inverseRatio) + (Color.red(color2) * ratio); float g = (Color.green(color1) * inverseRatio) + (Color.green(color2) * ratio); float b = (Color.blue(color1) * inverseRatio) + (Color.blue(color2) * ratio); return Color.argb((int) a, (int) r, (int) g, (int) b); } private static float lerp(float startValue, float endValue, float fraction, Interpolator interpolator) { if (interpolator != null) { fraction = interpolator.getInterpolation(fraction); } return AnimationUtils.lerp(startValue, endValue, fraction); } private static boolean rectEquals(Rect r, int left, int top, int right, int bottom) { return !(r.left != left || r.top != top || r.right != right || r.bottom != bottom); } }