Java tutorial
/* * Copyright (C) 2016 Bilibili * * 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 com.bilibili.magicasakura.utils; import android.content.Context; import android.content.res.TypedArray; import android.graphics.Color; import android.graphics.Rect; import android.graphics.drawable.Drawable; import android.graphics.drawable.GradientDrawable; import android.os.Build; import android.support.v4.graphics.ColorUtils; import android.util.AttributeSet; import android.util.Log; import android.util.TypedValue; import org.xmlpull.v1.XmlPullParser; import org.xmlpull.v1.XmlPullParserException; import java.io.IOException; import java.lang.reflect.Field; /** * @author xyczero617@gmail.com * @time 16/2/22 */ class GradientDrawableInflateImpl implements DrawableInflateDelegate { private static Field sPaddingField; private static Field sStPaddingField; private static Field sStGradientPositions; private static Field sStGradientAngle; @Override public Drawable inflateDrawable(Context context, XmlPullParser parser, AttributeSet attrs) throws XmlPullParserException, IOException { GradientDrawable gradientDrawable = new GradientDrawable(); inflateGradientRootElement(context, attrs, gradientDrawable); int type; final int innerDepth = parser.getDepth() + 1; int depth; while ((type = parser.next()) != XmlPullParser.END_DOCUMENT && ((depth = parser.getDepth()) >= innerDepth || type != XmlPullParser.END_TAG)) { if (type != XmlPullParser.START_TAG) { continue; } if (depth > innerDepth) { continue; } String name = parser.getName(); if (name.equals("size")) { final int width = DrawableUtils.getAttrDimensionPixelSize(context, attrs, android.R.attr.width); final int height = DrawableUtils.getAttrDimensionPixelSize(context, attrs, android.R.attr.height); gradientDrawable.setSize(width, height); } else if (name.equals("gradient") && Build.VERSION.SDK_INT > Build.VERSION_CODES.ICE_CREAM_SANDWICH_MR1) { final float centerX = getAttrFloatOrFraction(context, attrs, android.R.attr.centerX, 0.5f, 1.0f, 1.0f); final float centerY = getAttrFloatOrFraction(context, attrs, android.R.attr.centerY, 0.5f, 1.0f, 1.0f); gradientDrawable.setGradientCenter(centerX, centerY); final boolean useLevel = DrawableUtils.getAttrBoolean(context, attrs, android.R.attr.useLevel, false); gradientDrawable.setUseLevel(useLevel); final int gradientType = DrawableUtils.getAttrInt(context, attrs, android.R.attr.type, 0); gradientDrawable.setGradientType(gradientType); final int startColor = DrawableUtils.getAttrColor(context, attrs, android.R.attr.startColor, Color.TRANSPARENT); final int centerColor = DrawableUtils.getAttrColor(context, attrs, android.R.attr.centerColor, Color.TRANSPARENT); final int endColor = DrawableUtils.getAttrColor(context, attrs, android.R.attr.endColor, Color.TRANSPARENT); if (!DrawableUtils.getAttrHasValue(context, attrs, android.R.attr.centerColor)) { gradientDrawable.setColors(new int[] { startColor, endColor }); } else { gradientDrawable.setColors(new int[] { startColor, centerColor, endColor }); setStGradientPositions(gradientDrawable.getConstantState(), 0.0f, centerX != 0.5f ? centerX : centerY, 1f); } if (gradientType == GradientDrawable.LINEAR_GRADIENT) { int angle = (int) DrawableUtils.getAttrFloat(context, attrs, android.R.attr.angle, 0.0f); angle %= 360; if (angle % 45 != 0) { throw new XmlPullParserException( "<gradient> tag requires" + "'angle' attribute to " + "be a multiple of 45"); } setStGradientAngle(gradientDrawable.getConstantState(), angle); switch (angle) { case 0: gradientDrawable.setOrientation(GradientDrawable.Orientation.LEFT_RIGHT); break; case 45: gradientDrawable.setOrientation(GradientDrawable.Orientation.BL_TR); break; case 90: gradientDrawable.setOrientation(GradientDrawable.Orientation.BOTTOM_TOP); break; case 135: gradientDrawable.setOrientation(GradientDrawable.Orientation.BR_TL); break; case 180: gradientDrawable.setOrientation(GradientDrawable.Orientation.RIGHT_LEFT); break; case 225: gradientDrawable.setOrientation(GradientDrawable.Orientation.TR_BL); break; case 270: gradientDrawable.setOrientation(GradientDrawable.Orientation.TOP_BOTTOM); break; case 315: gradientDrawable.setOrientation(GradientDrawable.Orientation.TL_BR); break; } } else { setGradientRadius(context, attrs, gradientDrawable, gradientType); } } else if (name.equals("solid")) { int color = DrawableUtils.getAttrColor(context, attrs, android.R.attr.color, Color.TRANSPARENT); gradientDrawable.setColor(getAlphaColor(color, DrawableUtils.getAttrFloat(context, attrs, android.R.attr.alpha, 1.0f))); } else if (name.equals("stroke")) { final float alphaMod = DrawableUtils.getAttrFloat(context, attrs, android.R.attr.alpha, 1.0f); final int strokeColor = DrawableUtils.getAttrColor(context, attrs, android.R.attr.color, Color.TRANSPARENT); final int strokeWidth = DrawableUtils.getAttrDimensionPixelSize(context, attrs, android.R.attr.width); final float dashWidth = DrawableUtils.getAttrDimension(context, attrs, android.R.attr.dashWidth); if (dashWidth != 0.0f) { final float dashGap = DrawableUtils.getAttrDimension(context, attrs, android.R.attr.dashGap); gradientDrawable.setStroke(strokeWidth, getAlphaColor(strokeColor, alphaMod), dashWidth, dashGap); } else { gradientDrawable.setStroke(strokeWidth, getAlphaColor(strokeColor, alphaMod)); } } else if (name.equals("corners")) { final int radius = DrawableUtils.getAttrDimensionPixelSize(context, attrs, android.R.attr.radius); gradientDrawable.setCornerRadius(radius); final int topLeftRadius = DrawableUtils.getAttrDimensionPixelSize(context, attrs, android.R.attr.topLeftRadius, radius); final int topRightRadius = DrawableUtils.getAttrDimensionPixelSize(context, attrs, android.R.attr.topRightRadius, radius); final int bottomLeftRadius = DrawableUtils.getAttrDimensionPixelSize(context, attrs, android.R.attr.bottomLeftRadius, radius); final int bottomRightRadius = DrawableUtils.getAttrDimensionPixelSize(context, attrs, android.R.attr.bottomRightRadius, radius); if (topLeftRadius != radius || topRightRadius != radius || bottomLeftRadius != radius || bottomRightRadius != radius) { // The corner radii are specified in clockwise order (see Path.addRoundRect()) gradientDrawable.setCornerRadii( new float[] { topLeftRadius, topLeftRadius, topRightRadius, topRightRadius, bottomRightRadius, bottomRightRadius, bottomLeftRadius, bottomLeftRadius }); } } else if (name.equals("padding")) { final int paddingLeft = DrawableUtils.getAttrDimensionPixelOffset(context, attrs, android.R.attr.left); final int paddingTop = DrawableUtils.getAttrDimensionPixelOffset(context, attrs, android.R.attr.top); final int paddingRight = DrawableUtils.getAttrDimensionPixelOffset(context, attrs, android.R.attr.right); final int paddingBottom = DrawableUtils.getAttrDimensionPixelOffset(context, attrs, android.R.attr.bottom); if (paddingLeft != 0 || paddingTop != 0 || paddingRight != 0 || paddingBottom != 0) { final Rect pad = new Rect(); pad.set(paddingLeft, paddingTop, paddingRight, paddingBottom); try { if (sPaddingField == null) { sPaddingField = GradientDrawable.class.getDeclaredField("mPadding"); sPaddingField.setAccessible(true); } sPaddingField.set(gradientDrawable, pad); if (sStPaddingField == null) { sStPaddingField = Class .forName("android.graphics.drawable.GradientDrawable$GradientState") .getDeclaredField("mPadding"); sStPaddingField.setAccessible(true); } sStPaddingField.set(gradientDrawable.getConstantState(), pad); } catch (NoSuchFieldException e) { e.printStackTrace(); } catch (IllegalAccessException e) { e.printStackTrace(); } catch (ClassNotFoundException e) { e.printStackTrace(); } } } else { Log.w("drawable", "Bad element under <shape>: " + name); } } return gradientDrawable; } void inflateGradientRootElement(Context context, AttributeSet attrs, GradientDrawable gradientDrawable) { int shape = DrawableUtils.getAttrInt(context, attrs, android.R.attr.shape, GradientDrawable.RECTANGLE); gradientDrawable.setShape(shape); boolean dither = DrawableUtils.getAttrBoolean(context, attrs, android.R.attr.dither, false); gradientDrawable.setDither(dither); } void setGradientRadius(Context context, AttributeSet attrs, GradientDrawable drawable, int gradientType) throws XmlPullParserException { TypedArray a = DrawableUtils.obtainAttributes(context.getResources(), context.getTheme(), attrs, new int[] { android.R.attr.gradientRadius }); TypedValue value = a.peekValue(0); if (value != null) { boolean radiusRel = value.type == TypedValue.TYPE_FRACTION; drawable.setGradientRadius(radiusRel ? value.getFraction(1.0f, 1.0f) : value.getFloat()); } else if (gradientType == GradientDrawable.RADIAL_GRADIENT) { throw new XmlPullParserException( "<gradient> tag requires 'gradientRadius' " + "attribute with radial type"); } a.recycle(); } void setStGradientAngle(Drawable.ConstantState constantState, int angle) { try { if (sStGradientAngle == null) { sStGradientAngle = Class.forName("android.graphics.drawable.GradientDrawable$GradientState") .getDeclaredField("mAngle"); sStGradientAngle.setAccessible(true); } sStGradientAngle.set(constantState, angle); } catch (NoSuchFieldException e) { e.printStackTrace(); } catch (ClassNotFoundException e) { e.printStackTrace(); } catch (IllegalAccessException e) { e.printStackTrace(); } } void setStGradientPositions(Drawable.ConstantState constantState, float... positions) { try { if (sStGradientPositions == null) { sStGradientPositions = Class.forName("android.graphics.drawable.GradientDrawable$GradientState") .getDeclaredField("mPositions"); sStGradientPositions.setAccessible(true); } sStGradientPositions.set(constantState, positions); } catch (NoSuchFieldException e) { e.printStackTrace(); } catch (ClassNotFoundException e) { e.printStackTrace(); } catch (IllegalAccessException e) { e.printStackTrace(); } } float getAttrFloatOrFraction(Context context, AttributeSet attrs, int attr, float defaultValue, float base, float pbase) { TypedArray a = DrawableUtils.obtainAttributes(context.getResources(), context.getTheme(), attrs, new int[] { attr }); TypedValue tv = a.peekValue(0); float v = defaultValue; if (tv != null) { boolean isFraction = tv.type == TypedValue.TYPE_FRACTION; v = isFraction ? tv.getFraction(base, pbase) : tv.getFloat(); } a.recycle(); return v; } int getAlphaColor(int baseColor, float alpha) { return alpha != 1.0f ? ColorUtils.setAlphaComponent(baseColor, Math.round(Color.alpha(baseColor) * alpha)) : baseColor; } }