tools/layoutlib/bridge/src/com/android/layoutlib/bridge/impl/ResourceHelper.java - platform/frameworks/base - Git at Google

 /*
  * Copyright (C) 2008 The Android Open Source Project
  *
  * 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.android.layoutlib.bridge.impl;

 import com.android.SdkConstants;
 import com.android.ide.common.rendering.api.DensityBasedResourceValue;
 import com.android.ide.common.rendering.api.LayoutLog;
 import com.android.ide.common.rendering.api.RenderResources;
 import com.android.ide.common.rendering.api.ResourceValue;
 import com.android.internal.util.XmlUtils;
 import com.android.layoutlib.bridge.Bridge;
 import com.android.layoutlib.bridge.android.BridgeContext;
 import com.android.layoutlib.bridge.android.BridgeXmlBlockParser;
 import com.android.ninepatch.NinePatch;
 import com.android.ninepatch.NinePatchChunk;
 import com.android.resources.Density;

 import org.xmlpull.v1.XmlPullParser;
 import org.xmlpull.v1.XmlPullParserException;

 import android.annotation.NonNull;
 import android.content.res.ColorStateList;
 import android.content.res.Resources.Theme;
 import android.graphics.Bitmap;
 import android.graphics.Bitmap_Delegate;
 import android.graphics.NinePatch_Delegate;
 import android.graphics.Rect;
 import android.graphics.drawable.BitmapDrawable;
 import android.graphics.drawable.ColorDrawable;
 import android.graphics.drawable.Drawable;
 import android.graphics.drawable.NinePatchDrawable;
 import android.util.TypedValue;

 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.MalformedURLException;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;

 /**
  * Helper class to provide various conversion method used in handling android resources.
  */
 public final class ResourceHelper {

     private final static Pattern sFloatPattern = Pattern.compile("(-?[0-9]+(?:\\.[0-9]+)?)(.*)");
     private final static float[] sFloatOut = new float[1];

     private final static TypedValue mValue = new TypedValue();

     /**
      * Returns the color value represented by the given string value
      * @param value the color value
      * @return the color as an int
      * @throws NumberFormatException if the conversion failed.
      */
     public static int getColor(String value) {
         if (value != null) {
             if (!value.startsWith("#")) {
                 if (value.startsWith(SdkConstants.PREFIX_THEME_REF)) {
                     throw new NumberFormatException(String.format(
                             "Attribute '%s' not found. Are you using the right theme?", value));
                 }
                 throw new NumberFormatException(
                         String.format("Color value '%s' must start with #", value));
             }

             value = value.substring(1);

             // make sure it's not longer than 32bit
             if (value.length() > 8) {
                 throw new NumberFormatException(String.format(
                         "Color value '%s' is too long. Format is either" +
                         "#AARRGGBB, #RRGGBB, #RGB, or #ARGB",
                         value));
             }

             if (value.length() == 3) { // RGB format
                 char[] color = new char[8];
                 color[0] = color[1] = 'F';
                 color[2] = color[3] = value.charAt(0);
                 color[4] = color[5] = value.charAt(1);
                 color[6] = color[7] = value.charAt(2);
                 value = new String(color);
             } else if (value.length() == 4) { // ARGB format
                 char[] color = new char[8];
                 color[0] = color[1] = value.charAt(0);
                 color[2] = color[3] = value.charAt(1);
                 color[4] = color[5] = value.charAt(2);
                 color[6] = color[7] = value.charAt(3);
                 value = new String(color);
             } else if (value.length() == 6) {
                 value = "FF" + value;
             }

             // this is a RRGGBB or AARRGGBB value

             // Integer.parseInt will fail to parse strings like "ff191919", so we use
             // a Long, but cast the result back into an int, since we know that we're only
             // dealing with 32 bit values.
             return (int)Long.parseLong(value, 16);
         }

         throw new NumberFormatException();
     }

     public static ColorStateList getColorStateList(ResourceValue resValue, BridgeContext context) {
         String value = resValue.getValue();
         if (value != null && !RenderResources.REFERENCE_NULL.equals(value)) {
             // first check if the value is a file (xml most likely)
             File f = new File(value);
             if (f.isFile()) {
                 try {
                     // let the framework inflate the ColorStateList from the XML file, by
                     // providing an XmlPullParser
                     XmlPullParser parser = ParserFactory.create(f);

                     BridgeXmlBlockParser blockParser = new BridgeXmlBlockParser(
                             parser, context, resValue.isFramework());
                     try {
                         return ColorStateList.createFromXml(context.getResources(), blockParser);
                     } finally {
                         blockParser.ensurePopped();
                     }
                 } catch (XmlPullParserException e) {
                     Bridge.getLog().error(LayoutLog.TAG_BROKEN,
                             "Failed to configure parser for " + value, e, null /*data*/);
                     // we'll return null below.
                 } catch (Exception e) {
                     // this is an error and not warning since the file existence is
                     // checked before attempting to parse it.
                     Bridge.getLog().error(LayoutLog.TAG_RESOURCES_READ,
                             "Failed to parse file " + value, e, null /*data*/);

                     return null;
                 }
             } else {
                 // try to load the color state list from an int
                 try {
                     int color = ResourceHelper.getColor(value);
                     return ColorStateList.valueOf(color);
                 } catch (NumberFormatException e) {
                     Bridge.getLog().error(LayoutLog.TAG_RESOURCES_FORMAT,
                             "Failed to convert " + value + " into a ColorStateList", e,
                             null /*data*/);
                     return null;
                 }
             }
         }

         return null;
     }

     /**
      * Returns a drawable from the given value.
      * @param value The value that contains a path to a 9 patch, a bitmap or a xml based drawable,
      * or an hexadecimal color
      * @param context the current context
      */
     public static Drawable getDrawable(ResourceValue value, BridgeContext context) {
         return getDrawable(value, context, null);
     }

     /**
      * Returns a drawable from the given value.
      * @param value The value that contains a path to a 9 patch, a bitmap or a xml based drawable,
      * or an hexadecimal color
      * @param context the current context
      * @param theme the theme to be used to inflate the drawable.
      */
     public static Drawable getDrawable(ResourceValue value, BridgeContext context, Theme theme) {
         if (value == null) {
             return null;
         }
         String stringValue = value.getValue();
         if (RenderResources.REFERENCE_NULL.equals(stringValue)) {
             return null;
         }

         String lowerCaseValue = stringValue.toLowerCase();

         Density density = Density.MEDIUM;
         if (value instanceof DensityBasedResourceValue) {
             density =
                 ((DensityBasedResourceValue)value).getResourceDensity();
         }


         if (lowerCaseValue.endsWith(NinePatch.EXTENSION_9PATCH)) {
             File file = new File(stringValue);
             if (file.isFile()) {
                 try {
                     return getNinePatchDrawable(
                             new FileInputStream(file), density, value.isFramework(),
                             stringValue, context);
                 } catch (IOException e) {
                     // failed to read the file, we'll return null below.
                     Bridge.getLog().error(LayoutLog.TAG_RESOURCES_READ,
                             "Failed lot load " + file.getAbsolutePath(), e, null /*data*/);
                 }
             }

             return null;
         } else if (lowerCaseValue.endsWith(".xml")) {
             // create a block parser for the file
             File f = new File(stringValue);
             if (f.isFile()) {
                 try {
                     // let the framework inflate the Drawable from the XML file.
                     XmlPullParser parser = ParserFactory.create(f);

                     BridgeXmlBlockParser blockParser = new BridgeXmlBlockParser(
                             parser, context, value.isFramework());
                     try {
                         return Drawable.createFromXml(context.getResources(), blockParser, theme);
                     } finally {
                         blockParser.ensurePopped();
                     }
                 } catch (Exception e) {
                     // this is an error and not warning since the file existence is checked before
                     // attempting to parse it.
                     Bridge.getLog().error(null, "Failed to parse file " + stringValue,
                             e, null /*data*/);
                 }
             } else {
                 Bridge.getLog().error(LayoutLog.TAG_BROKEN,
                         String.format("File %s does not exist (or is not a file)", stringValue),
                         null /*data*/);
             }

             return null;
         } else {
             File bmpFile = new File(stringValue);
             if (bmpFile.isFile()) {
                 try {
                     Bitmap bitmap = Bridge.getCachedBitmap(stringValue,
                             value.isFramework() ? null : context.getProjectKey());

                     if (bitmap == null) {
                         bitmap = Bitmap_Delegate.createBitmap(bmpFile, false /*isMutable*/,
                                 density);
                         Bridge.setCachedBitmap(stringValue, bitmap,
                                 value.isFramework() ? null : context.getProjectKey());
                     }

                     return new BitmapDrawable(context.getResources(), bitmap);
                 } catch (IOException e) {
                     // we'll return null below
                     Bridge.getLog().error(LayoutLog.TAG_RESOURCES_READ,
                             "Failed lot load " + bmpFile.getAbsolutePath(), e, null /*data*/);
                 }
             } else {
                 // attempt to get a color from the value
                 try {
                     int color = getColor(stringValue);
                     return new ColorDrawable(color);
                 } catch (NumberFormatException e) {
                     // we'll return null below.
                     Bridge.getLog().error(LayoutLog.TAG_RESOURCES_FORMAT,
                             "Failed to convert " + stringValue + " into a drawable", e,
                             null /*data*/);
                 }
             }
         }

         return null;
     }

     private static Drawable getNinePatchDrawable(InputStream inputStream, Density density,
             boolean isFramework, String cacheKey, BridgeContext context) throws IOException {
         // see if we still have both the chunk and the bitmap in the caches
         NinePatchChunk chunk = Bridge.getCached9Patch(cacheKey,
                 isFramework ? null : context.getProjectKey());
         Bitmap bitmap = Bridge.getCachedBitmap(cacheKey,
                 isFramework ? null : context.getProjectKey());

         // if either chunk or bitmap is null, then we reload the 9-patch file.
         if (chunk == null || bitmap == null) {
             try {
                 NinePatch ninePatch = NinePatch.load(inputStream, true /*is9Patch*/,
                         false /* convert */);
                 if (ninePatch != null) {
                     if (chunk == null) {
                         chunk = ninePatch.getChunk();

                         Bridge.setCached9Patch(cacheKey, chunk,
                                 isFramework ? null : context.getProjectKey());
                     }

                     if (bitmap == null) {
                         bitmap = Bitmap_Delegate.createBitmap(ninePatch.getImage(),
                                 false /*isMutable*/,
                                 density);

                         Bridge.setCachedBitmap(cacheKey, bitmap,
                                 isFramework ? null : context.getProjectKey());
                     }
                 }
             } catch (MalformedURLException e) {
                 // URL is wrong, we'll return null below
             }
         }

         if (chunk != null && bitmap != null) {
             int[] padding = chunk.getPadding();
             Rect paddingRect = new Rect(padding[0], padding[1], padding[2], padding[3]);

             return new NinePatchDrawable(context.getResources(), bitmap,
                     NinePatch_Delegate.serialize(chunk),
                     paddingRect, null);
         }

         return null;
     }

     /**
      * Looks for an attribute in the current theme.
      *
      * @param resources the render resources
      * @param name the name of the attribute
      * @param defaultValue the default value.
      * @param isFrameworkAttr if the attribute is in android namespace
      * @return the value of the attribute or the default one if not found.
      */
     public static boolean getBooleanThemeValue(@NonNull RenderResources resources, String name,
             boolean isFrameworkAttr, boolean defaultValue) {
         ResourceValue value = resources.findItemInTheme(name, isFrameworkAttr);
         value = resources.resolveResValue(value);
         if (value == null) {
             return defaultValue;
         }
         return XmlUtils.convertValueToBoolean(value.getValue(), defaultValue);
     }

     // ------- TypedValue stuff
     // This is taken from //device/libs/utils/ResourceTypes.cpp

     private static final class UnitEntry {
         String name;
         int type;
         int unit;
         float scale;

         UnitEntry(String name, int type, int unit, float scale) {
             this.name = name;
             this.type = type;
             this.unit = unit;
             this.scale = scale;
         }
     }

     private final static UnitEntry[] sUnitNames = new UnitEntry[] {
         new UnitEntry("px", TypedValue.TYPE_DIMENSION, TypedValue.COMPLEX_UNIT_PX, 1.0f),
         new UnitEntry("dip", TypedValue.TYPE_DIMENSION, TypedValue.COMPLEX_UNIT_DIP, 1.0f),
         new UnitEntry("dp", TypedValue.TYPE_DIMENSION, TypedValue.COMPLEX_UNIT_DIP, 1.0f),
         new UnitEntry("sp", TypedValue.TYPE_DIMENSION, TypedValue.COMPLEX_UNIT_SP, 1.0f),
         new UnitEntry("pt", TypedValue.TYPE_DIMENSION, TypedValue.COMPLEX_UNIT_PT, 1.0f),
         new UnitEntry("in", TypedValue.TYPE_DIMENSION, TypedValue.COMPLEX_UNIT_IN, 1.0f),
         new UnitEntry("mm", TypedValue.TYPE_DIMENSION, TypedValue.COMPLEX_UNIT_MM, 1.0f),
         new UnitEntry("%", TypedValue.TYPE_FRACTION, TypedValue.COMPLEX_UNIT_FRACTION, 1.0f/100),
         new UnitEntry("%p", TypedValue.TYPE_FRACTION, TypedValue.COMPLEX_UNIT_FRACTION_PARENT, 1.0f/100),
     };

     /**
      * Returns the raw value from the given attribute float-type value string.
      * This object is only valid until the next call on to {@link ResourceHelper}.
      */
     public static TypedValue getValue(String attribute, String value, boolean requireUnit) {
         if (parseFloatAttribute(attribute, value, mValue, requireUnit)) {
             return mValue;
         }

         return null;
     }

     /**
      * Parse a float attribute and return the parsed value into a given TypedValue.
      * @param attribute the name of the attribute. Can be null if <var>requireUnit</var> is false.
      * @param value the string value of the attribute
      * @param outValue the TypedValue to receive the parsed value
      * @param requireUnit whether the value is expected to contain a unit.
      * @return true if success.
      */
     public static boolean parseFloatAttribute(String attribute, @NonNull String value,
             TypedValue outValue, boolean requireUnit) {
         assert !requireUnit || attribute != null;

         // remove the space before and after
         value = value.trim();
         int len = value.length();

         if (len <= 0) {
             return false;
         }

         // check that there's no non ascii characters.
         char[] buf = value.toCharArray();
         for (int i = 0 ; i < len ; i++) {
             if (buf[i] > 255) {
                 return false;
             }
         }

         // check the first character
         if ((buf[0] < '0' || buf[0] > '9') && buf[0] != '.' && buf[0] != '-' && buf[0] != '+') {
             return false;
         }

         // now look for the string that is after the float...
         Matcher m = sFloatPattern.matcher(value);
         if (m.matches()) {
             String f_str = m.group(1);
             String end = m.group(2);

             float f;
             try {
                 f = Float.parseFloat(f_str);
             } catch (NumberFormatException e) {
                 // this shouldn't happen with the regexp above.
                 return false;
             }

             if (end.length() > 0 && end.charAt(0) != ' ') {
                 // Might be a unit...
                 if (parseUnit(end, outValue, sFloatOut)) {
                     computeTypedValue(outValue, f, sFloatOut[0]);
                     return true;
                 }
                 return false;
             }

             // make sure it's only spaces at the end.
             end = end.trim();

             if (end.length() == 0) {
                 if (outValue != null) {
                     if (!requireUnit) {
                         outValue.type = TypedValue.TYPE_FLOAT;
                         outValue.data = Float.floatToIntBits(f);
                     } else {
                         // no unit when required? Use dp and out an error.
                         applyUnit(sUnitNames[1], outValue, sFloatOut);
                         computeTypedValue(outValue, f, sFloatOut[0]);

                         Bridge.getLog().error(LayoutLog.TAG_RESOURCES_RESOLVE,
                                 String.format(
                                         "Dimension \"%1$s\" in attribute \"%2$s\" is missing unit!",
                                         value, attribute),
                                 null);
                     }
                     return true;
                 }
             }
         }

         return false;
     }

     private static void computeTypedValue(TypedValue outValue, float value, float scale) {
         value *= scale;
         boolean neg = value < 0;
         if (neg) {
             value = -value;
         }
         long bits = (long)(value*(1<<23)+.5f);
         int radix;
         int shift;
         if ((bits&0x7fffff) == 0) {
             // Always use 23p0 if there is no fraction, just to make
             // things easier to read.
             radix = TypedValue.COMPLEX_RADIX_23p0;
             shift = 23;
         } else if ((bits&0xffffffffff800000L) == 0) {
             // Magnitude is zero -- can fit in 0 bits of precision.
             radix = TypedValue.COMPLEX_RADIX_0p23;
             shift = 0;
         } else if ((bits&0xffffffff80000000L) == 0) {
             // Magnitude can fit in 8 bits of precision.
             radix = TypedValue.COMPLEX_RADIX_8p15;
             shift = 8;
         } else if ((bits&0xffffff8000000000L) == 0) {
             // Magnitude can fit in 16 bits of precision.
             radix = TypedValue.COMPLEX_RADIX_16p7;
             shift = 16;
         } else {
             // Magnitude needs entire range, so no fractional part.
             radix = TypedValue.COMPLEX_RADIX_23p0;
             shift = 23;
         }
         int mantissa = (int)(
             (bits>>shift) & TypedValue.COMPLEX_MANTISSA_MASK);
         if (neg) {
             mantissa = (-mantissa) & TypedValue.COMPLEX_MANTISSA_MASK;
         }
         outValue.data |=
             (radix<<TypedValue.COMPLEX_RADIX_SHIFT)
             | (mantissa<<TypedValue.COMPLEX_MANTISSA_SHIFT);
     }

     private static boolean parseUnit(String str, TypedValue outValue, float[] outScale) {
         str = str.trim();

         for (UnitEntry unit : sUnitNames) {
             if (unit.name.equals(str)) {
                 applyUnit(unit, outValue, outScale);
                 return true;
             }
         }

         return false;
     }

     private static void applyUnit(UnitEntry unit, TypedValue outValue, float[] outScale) {
         outValue.type = unit.type;
         // COMPLEX_UNIT_SHIFT is 0 and hence intelliJ complains about it. Suppress the warning.
         //noinspection PointlessBitwiseExpression
         outValue.data = unit.unit << TypedValue.COMPLEX_UNIT_SHIFT;
         outScale[0] = unit.scale;
     }
 }
	/*
	* Copyright (C) 2008 The Android Open Source Project
	*
	* 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.android.layoutlib.bridge.impl;

	import com.android.SdkConstants;
	import com.android.ide.common.rendering.api.DensityBasedResourceValue;
	import com.android.ide.common.rendering.api.LayoutLog;
	import com.android.ide.common.rendering.api.RenderResources;
	import com.android.ide.common.rendering.api.ResourceValue;
	import com.android.internal.util.XmlUtils;
	import com.android.layoutlib.bridge.Bridge;
	import com.android.layoutlib.bridge.android.BridgeContext;
	import com.android.layoutlib.bridge.android.BridgeXmlBlockParser;
	import com.android.ninepatch.NinePatch;
	import com.android.ninepatch.NinePatchChunk;
	import com.android.resources.Density;

	import org.xmlpull.v1.XmlPullParser;
	import org.xmlpull.v1.XmlPullParserException;

	import android.annotation.NonNull;
	import android.content.res.ColorStateList;
	import android.content.res.Resources.Theme;
	import android.graphics.Bitmap;
	import android.graphics.Bitmap_Delegate;
	import android.graphics.NinePatch_Delegate;
	import android.graphics.Rect;
	import android.graphics.drawable.BitmapDrawable;
	import android.graphics.drawable.ColorDrawable;
	import android.graphics.drawable.Drawable;
	import android.graphics.drawable.NinePatchDrawable;
	import android.util.TypedValue;

	import java.io.File;
	import java.io.FileInputStream;
	import java.io.IOException;
	import java.io.InputStream;
	import java.net.MalformedURLException;
	import java.util.regex.Matcher;
	import java.util.regex.Pattern;

	/**
	* Helper class to provide various conversion method used in handling android resources.
	*/
	public final class ResourceHelper {

	private final static Pattern sFloatPattern = Pattern.compile("(-?[0-9]+(?:\\.[0-9]+)?)(.*)");
	private final static float[] sFloatOut = new float[1];

	private final static TypedValue mValue = new TypedValue();

	/**
	* Returns the color value represented by the given string value
	* @param value the color value
	* @return the color as an int
	* @throws NumberFormatException if the conversion failed.
	*/
	public static int getColor(String value) {
	if (value != null) {
	if (!value.startsWith("#")) {
	if (value.startsWith(SdkConstants.PREFIX_THEME_REF)) {
	throw new NumberFormatException(String.format(
	"Attribute '%s' not found. Are you using the right theme?", value));
	}
	throw new NumberFormatException(
	String.format("Color value '%s' must start with #", value));
	}

	value = value.substring(1);

	// make sure it's not longer than 32bit
	if (value.length() > 8) {
	throw new NumberFormatException(String.format(
	"Color value '%s' is too long. Format is either" +
	"#AARRGGBB, #RRGGBB, #RGB, or #ARGB",
	value));
	}

	if (value.length() == 3) { // RGB format
	char[] color = new char[8];
	color[0] = color[1] = 'F';
	color[2] = color[3] = value.charAt(0);
	color[4] = color[5] = value.charAt(1);
	color[6] = color[7] = value.charAt(2);
	value = new String(color);
	} else if (value.length() == 4) { // ARGB format
	char[] color = new char[8];
	color[0] = color[1] = value.charAt(0);
	color[2] = color[3] = value.charAt(1);
	color[4] = color[5] = value.charAt(2);
	color[6] = color[7] = value.charAt(3);
	value = new String(color);
	} else if (value.length() == 6) {
	value = "FF" + value;
	}

	// this is a RRGGBB or AARRGGBB value

	// Integer.parseInt will fail to parse strings like "ff191919", so we use
	// a Long, but cast the result back into an int, since we know that we're only
	// dealing with 32 bit values.
	return (int)Long.parseLong(value, 16);
	}

	throw new NumberFormatException();
	}

	public static ColorStateList getColorStateList(ResourceValue resValue, BridgeContext context) {
	String value = resValue.getValue();
	if (value != null && !RenderResources.REFERENCE_NULL.equals(value)) {
	// first check if the value is a file (xml most likely)
	File f = new File(value);
	if (f.isFile()) {
	try {
	// let the framework inflate the ColorStateList from the XML file, by
	// providing an XmlPullParser
	XmlPullParser parser = ParserFactory.create(f);

	BridgeXmlBlockParser blockParser = new BridgeXmlBlockParser(
	parser, context, resValue.isFramework());
	try {
	return ColorStateList.createFromXml(context.getResources(), blockParser);
	} finally {
	blockParser.ensurePopped();
	}
	} catch (XmlPullParserException e) {
	Bridge.getLog().error(LayoutLog.TAG_BROKEN,
	"Failed to configure parser for " + value, e, null /data/);
	// we'll return null below.
	} catch (Exception e) {
	// this is an error and not warning since the file existence is
	// checked before attempting to parse it.
	Bridge.getLog().error(LayoutLog.TAG_RESOURCES_READ,
	"Failed to parse file " + value, e, null /data/);

	return null;
	}
	} else {
	// try to load the color state list from an int
	try {
	int color = ResourceHelper.getColor(value);
	return ColorStateList.valueOf(color);
	} catch (NumberFormatException e) {
	Bridge.getLog().error(LayoutLog.TAG_RESOURCES_FORMAT,
	"Failed to convert " + value + " into a ColorStateList", e,
	null /data/);
	return null;
	}
	}
	}

	return null;
	}

	/**
	* Returns a drawable from the given value.
	* @param value The value that contains a path to a 9 patch, a bitmap or a xml based drawable,
	* or an hexadecimal color
	* @param context the current context
	*/
	public static Drawable getDrawable(ResourceValue value, BridgeContext context) {
	return getDrawable(value, context, null);
	}

	/**
	* Returns a drawable from the given value.
	* @param value The value that contains a path to a 9 patch, a bitmap or a xml based drawable,
	* or an hexadecimal color
	* @param context the current context
	* @param theme the theme to be used to inflate the drawable.
	*/
	public static Drawable getDrawable(ResourceValue value, BridgeContext context, Theme theme) {
	if (value == null) {
	return null;
	}
	String stringValue = value.getValue();
	if (RenderResources.REFERENCE_NULL.equals(stringValue)) {
	return null;
	}

	String lowerCaseValue = stringValue.toLowerCase();

	Density density = Density.MEDIUM;
	if (value instanceof DensityBasedResourceValue) {
	density =
	((DensityBasedResourceValue)value).getResourceDensity();
	}


	if (lowerCaseValue.endsWith(NinePatch.EXTENSION_9PATCH)) {
	File file = new File(stringValue);
	if (file.isFile()) {
	try {
	return getNinePatchDrawable(
	new FileInputStream(file), density, value.isFramework(),
	stringValue, context);
	} catch (IOException e) {
	// failed to read the file, we'll return null below.
	Bridge.getLog().error(LayoutLog.TAG_RESOURCES_READ,
	"Failed lot load " + file.getAbsolutePath(), e, null /data/);
	}
	}

	return null;
	} else if (lowerCaseValue.endsWith(".xml")) {
	// create a block parser for the file
	File f = new File(stringValue);
	if (f.isFile()) {
	try {
	// let the framework inflate the Drawable from the XML file.
	XmlPullParser parser = ParserFactory.create(f);

	BridgeXmlBlockParser blockParser = new BridgeXmlBlockParser(
	parser, context, value.isFramework());
	try {
	return Drawable.createFromXml(context.getResources(), blockParser, theme);
	} finally {
	blockParser.ensurePopped();
	}
	} catch (Exception e) {
	// this is an error and not warning since the file existence is checked before
	// attempting to parse it.
	Bridge.getLog().error(null, "Failed to parse file " + stringValue,
	e, null /data/);
	}
	} else {
	Bridge.getLog().error(LayoutLog.TAG_BROKEN,
	String.format("File %s does not exist (or is not a file)", stringValue),
	null /data/);
	}

	return null;
	} else {
	File bmpFile = new File(stringValue);
	if (bmpFile.isFile()) {
	try {
	Bitmap bitmap = Bridge.getCachedBitmap(stringValue,
	value.isFramework() ? null : context.getProjectKey());

	if (bitmap == null) {
	bitmap = Bitmap_Delegate.createBitmap(bmpFile, false /isMutable/,
	density);
	Bridge.setCachedBitmap(stringValue, bitmap,
	value.isFramework() ? null : context.getProjectKey());
	}

	return new BitmapDrawable(context.getResources(), bitmap);
	} catch (IOException e) {
	// we'll return null below
	Bridge.getLog().error(LayoutLog.TAG_RESOURCES_READ,
	"Failed lot load " + bmpFile.getAbsolutePath(), e, null /data/);
	}
	} else {
	// attempt to get a color from the value
	try {
	int color = getColor(stringValue);
	return new ColorDrawable(color);
	} catch (NumberFormatException e) {
	// we'll return null below.
	Bridge.getLog().error(LayoutLog.TAG_RESOURCES_FORMAT,
	"Failed to convert " + stringValue + " into a drawable", e,
	null /data/);
	}
	}
	}

	return null;
	}

	private static Drawable getNinePatchDrawable(InputStream inputStream, Density density,
	boolean isFramework, String cacheKey, BridgeContext context) throws IOException {
	// see if we still have both the chunk and the bitmap in the caches
	NinePatchChunk chunk = Bridge.getCached9Patch(cacheKey,
	isFramework ? null : context.getProjectKey());
	Bitmap bitmap = Bridge.getCachedBitmap(cacheKey,
	isFramework ? null : context.getProjectKey());

	// if either chunk or bitmap is null, then we reload the 9-patch file.
	if (chunk == null \|\| bitmap == null) {
	try {
	NinePatch ninePatch = NinePatch.load(inputStream, true /is9Patch/,
	false /* convert */);
	if (ninePatch != null) {
	if (chunk == null) {
	chunk = ninePatch.getChunk();

	Bridge.setCached9Patch(cacheKey, chunk,
	isFramework ? null : context.getProjectKey());
	}

	if (bitmap == null) {
	bitmap = Bitmap_Delegate.createBitmap(ninePatch.getImage(),
	false /isMutable/,
	density);

	Bridge.setCachedBitmap(cacheKey, bitmap,
	isFramework ? null : context.getProjectKey());
	}
	}
	} catch (MalformedURLException e) {
	// URL is wrong, we'll return null below
	}
	}

	if (chunk != null && bitmap != null) {
	int[] padding = chunk.getPadding();
	Rect paddingRect = new Rect(padding[0], padding[1], padding[2], padding[3]);

	return new NinePatchDrawable(context.getResources(), bitmap,
	NinePatch_Delegate.serialize(chunk),
	paddingRect, null);
	}

	return null;
	}

	/**
	* Looks for an attribute in the current theme.
	*
	* @param resources the render resources
	* @param name the name of the attribute
	* @param defaultValue the default value.
	* @param isFrameworkAttr if the attribute is in android namespace
	* @return the value of the attribute or the default one if not found.
	*/
	public static boolean getBooleanThemeValue(@NonNull RenderResources resources, String name,
	boolean isFrameworkAttr, boolean defaultValue) {
	ResourceValue value = resources.findItemInTheme(name, isFrameworkAttr);
	value = resources.resolveResValue(value);
	if (value == null) {
	return defaultValue;
	}
	return XmlUtils.convertValueToBoolean(value.getValue(), defaultValue);
	}

	// ------- TypedValue stuff
	// This is taken from //device/libs/utils/ResourceTypes.cpp

	private static final class UnitEntry {
	String name;
	int type;
	int unit;
	float scale;

	UnitEntry(String name, int type, int unit, float scale) {
	this.name = name;
	this.type = type;
	this.unit = unit;
	this.scale = scale;
	}
	}

	private final static UnitEntry[] sUnitNames = new UnitEntry[] {
	new UnitEntry("px", TypedValue.TYPE_DIMENSION, TypedValue.COMPLEX_UNIT_PX, 1.0f),
	new UnitEntry("dip", TypedValue.TYPE_DIMENSION, TypedValue.COMPLEX_UNIT_DIP, 1.0f),
	new UnitEntry("dp", TypedValue.TYPE_DIMENSION, TypedValue.COMPLEX_UNIT_DIP, 1.0f),
	new UnitEntry("sp", TypedValue.TYPE_DIMENSION, TypedValue.COMPLEX_UNIT_SP, 1.0f),
	new UnitEntry("pt", TypedValue.TYPE_DIMENSION, TypedValue.COMPLEX_UNIT_PT, 1.0f),
	new UnitEntry("in", TypedValue.TYPE_DIMENSION, TypedValue.COMPLEX_UNIT_IN, 1.0f),
	new UnitEntry("mm", TypedValue.TYPE_DIMENSION, TypedValue.COMPLEX_UNIT_MM, 1.0f),
	new UnitEntry("%", TypedValue.TYPE_FRACTION, TypedValue.COMPLEX_UNIT_FRACTION, 1.0f/100),
	new UnitEntry("%p", TypedValue.TYPE_FRACTION, TypedValue.COMPLEX_UNIT_FRACTION_PARENT, 1.0f/100),
	};

	/**
	* Returns the raw value from the given attribute float-type value string.
	* This object is only valid until the next call on to {@link ResourceHelper}.
	*/
	public static TypedValue getValue(String attribute, String value, boolean requireUnit) {
	if (parseFloatAttribute(attribute, value, mValue, requireUnit)) {
	return mValue;
	}

	return null;
	}

	/**
	* Parse a float attribute and return the parsed value into a given TypedValue.
	* @param attribute the name of the attribute. Can be null if <var>requireUnit</var> is false.
	* @param value the string value of the attribute
	* @param outValue the TypedValue to receive the parsed value
	* @param requireUnit whether the value is expected to contain a unit.
	* @return true if success.
	*/
	public static boolean parseFloatAttribute(String attribute, @NonNull String value,
	TypedValue outValue, boolean requireUnit) {
	assert !requireUnit \|\| attribute != null;

	// remove the space before and after
	value = value.trim();
	int len = value.length();

	if (len <= 0) {
	return false;
	}

	// check that there's no non ascii characters.
	char[] buf = value.toCharArray();
	for (int i = 0 ; i < len ; i++) {
	if (buf[i] > 255) {
	return false;
	}
	}

	// check the first character
	if ((buf[0] < '0' \|\| buf[0] > '9') && buf[0] != '.' && buf[0] != '-' && buf[0] != '+') {
	return false;
	}

	// now look for the string that is after the float...
	Matcher m = sFloatPattern.matcher(value);
	if (m.matches()) {
	String f_str = m.group(1);
	String end = m.group(2);

	float f;
	try {
	f = Float.parseFloat(f_str);
	} catch (NumberFormatException e) {
	// this shouldn't happen with the regexp above.
	return false;
	}

	if (end.length() > 0 && end.charAt(0) != ' ') {
	// Might be a unit...
	if (parseUnit(end, outValue, sFloatOut)) {
	computeTypedValue(outValue, f, sFloatOut[0]);
	return true;
	}
	return false;
	}

	// make sure it's only spaces at the end.
	end = end.trim();

	if (end.length() == 0) {
	if (outValue != null) {
	if (!requireUnit) {
	outValue.type = TypedValue.TYPE_FLOAT;
	outValue.data = Float.floatToIntBits(f);
	} else {
	// no unit when required? Use dp and out an error.
	applyUnit(sUnitNames[1], outValue, sFloatOut);
	computeTypedValue(outValue, f, sFloatOut[0]);

	Bridge.getLog().error(LayoutLog.TAG_RESOURCES_RESOLVE,
	String.format(
	"Dimension \"%1$s\" in attribute \"%2$s\" is missing unit!",
	value, attribute),
	null);
	}
	return true;
	}
	}
	}

	return false;
	}

	private static void computeTypedValue(TypedValue outValue, float value, float scale) {
	value *= scale;
	boolean neg = value < 0;
	if (neg) {
	value = -value;
	}
	long bits = (long)(value*(1<<23)+.5f);
	int radix;
	int shift;
	if ((bits&0x7fffff) == 0) {
	// Always use 23p0 if there is no fraction, just to make
	// things easier to read.
	radix = TypedValue.COMPLEX_RADIX_23p0;
	shift = 23;
	} else if ((bits&0xffffffffff800000L) == 0) {
	// Magnitude is zero -- can fit in 0 bits of precision.
	radix = TypedValue.COMPLEX_RADIX_0p23;
	shift = 0;
	} else if ((bits&0xffffffff80000000L) == 0) {
	// Magnitude can fit in 8 bits of precision.
	radix = TypedValue.COMPLEX_RADIX_8p15;
	shift = 8;
	} else if ((bits&0xffffff8000000000L) == 0) {
	// Magnitude can fit in 16 bits of precision.
	radix = TypedValue.COMPLEX_RADIX_16p7;
	shift = 16;
	} else {
	// Magnitude needs entire range, so no fractional part.
	radix = TypedValue.COMPLEX_RADIX_23p0;
	shift = 23;
	}
	int mantissa = (int)(
	(bits>>shift) & TypedValue.COMPLEX_MANTISSA_MASK);
	if (neg) {
	mantissa = (-mantissa) & TypedValue.COMPLEX_MANTISSA_MASK;
	}
	outValue.data \|=
	(radix<<TypedValue.COMPLEX_RADIX_SHIFT)
	\| (mantissa<<TypedValue.COMPLEX_MANTISSA_SHIFT);
	}

	private static boolean parseUnit(String str, TypedValue outValue, float[] outScale) {
	str = str.trim();

	for (UnitEntry unit : sUnitNames) {
	if (unit.name.equals(str)) {
	applyUnit(unit, outValue, outScale);
	return true;
	}
	}

	return false;
	}

	private static void applyUnit(UnitEntry unit, TypedValue outValue, float[] outScale) {
	outValue.type = unit.type;
	// COMPLEX_UNIT_SHIFT is 0 and hence intelliJ complains about it. Suppress the warning.
	//noinspection PointlessBitwiseExpression
	outValue.data = unit.unit << TypedValue.COMPLEX_UNIT_SHIFT;
	outScale[0] = unit.scale;
	}
	}