2.4/dev/core/src/com/google/gwt/dev/shell/JsValueGlue.java - gwt - Git at Google

 /*
  * Copyright 2008 Google Inc.
  *
  * 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.google.gwt.dev.shell;

 import com.google.gwt.core.ext.TreeLogger;
 import com.google.gwt.dev.util.TypeInfo;

 import java.lang.reflect.Constructor;
 import java.lang.reflect.Field;
 import java.lang.reflect.InvocationTargetException;

 /**
  * Glue layer that performs GWT-specific operations on JsValues. Used to isolate
  * HostedModeExceptions/etc from JsValue code
  */
 public final class JsValueGlue {
   public static final String HOSTED_MODE_REFERENCE = "hostedModeReference";
   public static final String JSO_CLASS = "com.google.gwt.core.client.JavaScriptObject";
   public static final String JSO_IMPL_CLASS = "com.google.gwt.core.client.JavaScriptObject$";

   /**
    * Create a JavaScriptObject instance referring to this JavaScript object.
    *
    * @param classLoader the classLoader to create from
    * @return the constructed JavaScriptObject
    */
   public static Object createJavaScriptObject(JsValue value,
       CompilingClassLoader classLoader) {
     Throwable caught;
     try {
       // See if there's already a wrapper object (assures identity comparison).
       Object jso = classLoader.getCachedJso(value.getJavaScriptObjectPointer());
       if (jso != null) {
         return jso;
       }

       // Instantiate the JSO class.
       Class<?> jsoType = Class.forName(JSO_IMPL_CLASS, true, classLoader);
       Constructor<?> ctor = jsoType.getDeclaredConstructor();
       ctor.setAccessible(true);
       jso = ctor.newInstance();

       // Set the reference field to this JsValue using reflection.
       Field referenceField = jsoType.getField(HOSTED_MODE_REFERENCE);
       referenceField.set(jso, value);

       classLoader.putCachedJso(value.getJavaScriptObjectPointer(), jso);
       return jso;
     } catch (InstantiationException e) {
       caught = e;
     } catch (IllegalAccessException e) {
       caught = e;
     } catch (SecurityException e) {
       caught = e;
     } catch (NoSuchMethodException e) {
       caught = e;
     } catch (IllegalArgumentException e) {
       caught = e;
     } catch (InvocationTargetException e) {
       caught = e;
     } catch (ClassNotFoundException e) {
       caught = e;
     } catch (NoSuchFieldException e) {
       caught = e;
     }
     throw new RuntimeException("Error creating JavaScript object", caught);
   }

   /**
    * Return an object containing the value JavaScript object as a specified
    * type.
    *
    * @param value the JavaScript value
    * @param type expected type of the returned object
    * @param msgPrefix a prefix for error/warning messages
    * @return the object reference
    * @throws com.google.gwt.dev.shell.HostedModeException if the JavaScript
    *     object is not assignable to the supplied type.
    */
   @SuppressWarnings("unchecked")
   public static <T> T get(JsValue value, CompilingClassLoader cl,
       Class<T> type, String msgPrefix) {

     if (type.isPrimitive()) {
       if (type == Boolean.TYPE) {
         if (!value.isBoolean()) {
           throw new HostedModeException(msgPrefix + ": JS value of type "
               + value.getTypeString() + ", expected boolean");
         }
         return (T) Boolean.valueOf(value.getBoolean());
       } else if (type == Byte.TYPE) {
         return (T) Byte.valueOf((byte) getIntRange(value, Byte.MIN_VALUE,
             Byte.MAX_VALUE, "byte", msgPrefix));
       } else if (type == Character.TYPE) {
         return (T) Character.valueOf((char) getIntRange(value,
             Character.MIN_VALUE, Character.MAX_VALUE, "char", msgPrefix));
       } else if (type == Double.TYPE) {
         if (!value.isNumber()) {
           throw new HostedModeException(msgPrefix + ": JS value of type "
               + value.getTypeString() + ", expected double");
         }
         return (T) Double.valueOf(value.getNumber());
       } else if (type == Float.TYPE) {
         if (!value.isNumber()) {
           throw new HostedModeException(msgPrefix + ": JS value of type "
               + value.getTypeString() + ", expected float");
         }
         double doubleVal = value.getNumber();

         // Check for small changes near MIN_VALUE and replace with the
         // actual end point value, in case it is being used as a sentinel
         // value. This test works by the subtraction result rounding off to
         // zero if the delta is not representable in a float.
         // TODO(jat): add similar test for MAX_VALUE if we have a JS
         // platform that alters the value while converting to/from strings.
         if ((float) (doubleVal - Float.MIN_VALUE) == 0.0f) {
           doubleVal = Float.MIN_VALUE;
         }

         float floatVal = (float) doubleVal;
         if (Float.isInfinite(floatVal) && !Double.isInfinite(doubleVal)) {
           // in this case we had overflow from the double value which was
           // outside the range of supported float values, and the cast
           // converted it to infinity. Since this lost data, we treat this
           // as an error in hosted mode.
           throw new HostedModeException(msgPrefix + ": JS value " + doubleVal
               + " out of range for a float");
         }
         return (T) Float.valueOf(floatVal);
       } else if (type == Integer.TYPE) {
         return (T) Integer.valueOf(getIntRange(value, Integer.MIN_VALUE,
             Integer.MAX_VALUE, "int", msgPrefix));
       } else if (type == Long.TYPE) {
         if (!value.isWrappedJavaObject()) {
           throw new HostedModeException(msgPrefix + ": JS value of type "
               + value.getTypeString() + ", expected Java long");
         }
         JavaLong javaLong = (JavaLong) value.getWrappedJavaObject();
         return (T) Long.valueOf(javaLong.longValue());
       } else if (type == Short.TYPE) {
         return (T) Short.valueOf((short) getIntRange(value, Short.MIN_VALUE,
             Short.MAX_VALUE, "short", msgPrefix));
       }
     }

     if (value.isNull() || value.isUndefined()) {
       return null;
     }
     if (value.isWrappedJavaObject()) {
       return type.cast(value.getWrappedJavaObject());
     }
     if (value.isString()) {
       return type.cast(value.getString());
     }
     if (value.isJavaScriptObject()) {
       return type.cast(createJavaScriptObject(value, cl));
     }

     // Just don't know what do to with this.
     /*
      * TODO (amitmanjhi): does throwing a HostedModeException here and catching
      * a RuntimeException in user test
      * com.google.gwt.dev.jjs.test.HostedTest::testObjectReturns() make sense
      */
     throw new IllegalArgumentException(msgPrefix + ": JS value of type "
         + value.getTypeString() + ", expected "
         + TypeInfo.getSourceRepresentation(type));
   }

   /**
    * Set the underlying value.
    *
    * @param value JsValue to set
    * @param type static type of the object
    * @param obj the object to store in the JS value
    */
   public static void set(JsValue value, CompilingClassLoader cl, Class<?> type,
       Object obj) {
     if (type.isPrimitive()) {
       if (type == Boolean.TYPE) {
         value.setBoolean(((Boolean) obj).booleanValue());
       } else if (type == Byte.TYPE) {
         value.setInt(((Byte) obj).byteValue());
       } else if (type == Character.TYPE) {
         value.setInt(((Character) obj).charValue());
       } else if (type == Double.TYPE) {
         value.setDouble(((Double) obj).doubleValue());
       } else if (type == Float.TYPE) {
         value.setDouble(((Float) obj).floatValue());
       } else if (type == Integer.TYPE) {
         value.setInt(((Integer) obj).intValue());
       } else if (type == Long.TYPE) {
         long longVal = ((Long) obj).longValue();
         value.setWrappedJavaObject(cl, new JavaLong(longVal));
       } else if (type == Short.TYPE) {
         value.setInt(((Short) obj).shortValue());
       } else if (type == Void.TYPE) {
         value.setUndefined();
       } else {
         throw new HostedModeException("Cannot marshal primitive type " + type);
       }
     } else if (obj == null) {
       value.setNull();
     } else {
       // not a boxed primitive
       try {
         Class<?> jsoType = Class.forName(JSO_IMPL_CLASS, false, cl);
         if (jsoType == obj.getClass()) {
           JsValue jsObject = getUnderlyingObject(obj);
           value.setValue(jsObject);
           return;
         }
       } catch (ClassNotFoundException e) {
         // Ignore the exception, if we can't find the class then obviously we
         // don't have to worry about o being one
       }

       // Fall through case: Object.
       if (!type.isInstance(obj)) {
         throw new HostedModeException("object is of type "
             + obj.getClass().getName() + ", expected " + type.getName());
       }
       if (obj instanceof String) {
         value.setString((String) obj);
       } else {
         value.setWrappedJavaObject(cl, obj);
       }
     }
   }

   private static int getIntRange(JsValue value, int low, int high,
       String typeName, String msgPrefix) {
     int intVal;
     if (value.isInt()) {
       intVal = value.getInt();
       if (intVal < low || intVal > high) {
         throw new HostedModeException(msgPrefix + ": JS int value " + intVal
             + " out of range for a " + typeName);
       }
     } else if (value.isNumber()) {
       double doubleVal = value.getNumber();
       if (doubleVal < low || doubleVal > high) {
         throw new HostedModeException(msgPrefix + ": JS double value "
             + doubleVal + " out of range for a " + typeName);
       }
       intVal = (int) doubleVal;
       if (intVal != doubleVal) {
         ModuleSpace.getLogger().log(TreeLogger.WARN,
             msgPrefix + ": Rounding double (" + doubleVal + ") to int for "
             + typeName, null);
       }
     } else {
       throw new HostedModeException(msgPrefix + ": JS value of type "
           + value.getTypeString() + ", expected " + typeName);
     }
     return intVal;
   }

   /**
    * Returns the underlying JsValue from a JavaScriptObject instance.
    *
    * The tricky part is that it is in a different ClassLoader so therefore can't
    * be specified directly. The type is specified as Object, and reflection is
    * used to retrieve the reference field.
    *
    * @param jso the instance of JavaScriptObject to retrieve the JsValue from.
    * @return the JsValue representing the JavaScript object
    */
   private static JsValue getUnderlyingObject(Object jso) {
     Throwable caught;
     try {
       Field referenceField = jso.getClass().getField(HOSTED_MODE_REFERENCE);
       referenceField.setAccessible(true);
       return (JsValue) referenceField.get(jso);
     } catch (IllegalAccessException e) {
       caught = e;
     } catch (SecurityException e) {
       caught = e;
     } catch (NoSuchFieldException e) {
       caught = e;
     }
     throw new RuntimeException("Error reading " + HOSTED_MODE_REFERENCE, caught);
   }

   private JsValueGlue() {
   }
 }
	/*
	* Copyright 2008 Google Inc.
	*
	* 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.google.gwt.dev.shell;

	import com.google.gwt.core.ext.TreeLogger;
	import com.google.gwt.dev.util.TypeInfo;

	import java.lang.reflect.Constructor;
	import java.lang.reflect.Field;
	import java.lang.reflect.InvocationTargetException;

	/**
	* Glue layer that performs GWT-specific operations on JsValues. Used to isolate
	* HostedModeExceptions/etc from JsValue code
	*/
	public final class JsValueGlue {
	public static final String HOSTED_MODE_REFERENCE = "hostedModeReference";
	public static final String JSO_CLASS = "com.google.gwt.core.client.JavaScriptObject";
	public static final String JSO_IMPL_CLASS = "com.google.gwt.core.client.JavaScriptObject$";

	/**
	* Create a JavaScriptObject instance referring to this JavaScript object.
	*
	* @param classLoader the classLoader to create from
	* @return the constructed JavaScriptObject
	*/
	public static Object createJavaScriptObject(JsValue value,
	CompilingClassLoader classLoader) {
	Throwable caught;
	try {
	// See if there's already a wrapper object (assures identity comparison).
	Object jso = classLoader.getCachedJso(value.getJavaScriptObjectPointer());
	if (jso != null) {
	return jso;
	}

	// Instantiate the JSO class.
	Class<?> jsoType = Class.forName(JSO_IMPL_CLASS, true, classLoader);
	Constructor<?> ctor = jsoType.getDeclaredConstructor();
	ctor.setAccessible(true);
	jso = ctor.newInstance();

	// Set the reference field to this JsValue using reflection.
	Field referenceField = jsoType.getField(HOSTED_MODE_REFERENCE);
	referenceField.set(jso, value);

	classLoader.putCachedJso(value.getJavaScriptObjectPointer(), jso);
	return jso;
	} catch (InstantiationException e) {
	caught = e;
	} catch (IllegalAccessException e) {
	caught = e;
	} catch (SecurityException e) {
	caught = e;
	} catch (NoSuchMethodException e) {
	caught = e;
	} catch (IllegalArgumentException e) {
	caught = e;
	} catch (InvocationTargetException e) {
	caught = e;
	} catch (ClassNotFoundException e) {
	caught = e;
	} catch (NoSuchFieldException e) {
	caught = e;
	}
	throw new RuntimeException("Error creating JavaScript object", caught);
	}

	/**
	* Return an object containing the value JavaScript object as a specified
	* type.
	*
	* @param value the JavaScript value
	* @param type expected type of the returned object
	* @param msgPrefix a prefix for error/warning messages
	* @return the object reference
	* @throws com.google.gwt.dev.shell.HostedModeException if the JavaScript
	* object is not assignable to the supplied type.
	*/
	@SuppressWarnings("unchecked")
	public static <T> T get(JsValue value, CompilingClassLoader cl,
	Class<T> type, String msgPrefix) {

	if (type.isPrimitive()) {
	if (type == Boolean.TYPE) {
	if (!value.isBoolean()) {
	throw new HostedModeException(msgPrefix + ": JS value of type "
	+ value.getTypeString() + ", expected boolean");
	}
	return (T) Boolean.valueOf(value.getBoolean());
	} else if (type == Byte.TYPE) {
	return (T) Byte.valueOf((byte) getIntRange(value, Byte.MIN_VALUE,
	Byte.MAX_VALUE, "byte", msgPrefix));
	} else if (type == Character.TYPE) {
	return (T) Character.valueOf((char) getIntRange(value,
	Character.MIN_VALUE, Character.MAX_VALUE, "char", msgPrefix));
	} else if (type == Double.TYPE) {
	if (!value.isNumber()) {
	throw new HostedModeException(msgPrefix + ": JS value of type "
	+ value.getTypeString() + ", expected double");
	}
	return (T) Double.valueOf(value.getNumber());
	} else if (type == Float.TYPE) {
	if (!value.isNumber()) {
	throw new HostedModeException(msgPrefix + ": JS value of type "
	+ value.getTypeString() + ", expected float");
	}
	double doubleVal = value.getNumber();

	// Check for small changes near MIN_VALUE and replace with the
	// actual end point value, in case it is being used as a sentinel
	// value. This test works by the subtraction result rounding off to
	// zero if the delta is not representable in a float.
	// TODO(jat): add similar test for MAX_VALUE if we have a JS
	// platform that alters the value while converting to/from strings.
	if ((float) (doubleVal - Float.MIN_VALUE) == 0.0f) {
	doubleVal = Float.MIN_VALUE;
	}

	float floatVal = (float) doubleVal;
	if (Float.isInfinite(floatVal) && !Double.isInfinite(doubleVal)) {
	// in this case we had overflow from the double value which was
	// outside the range of supported float values, and the cast
	// converted it to infinity. Since this lost data, we treat this
	// as an error in hosted mode.
	throw new HostedModeException(msgPrefix + ": JS value " + doubleVal
	+ " out of range for a float");
	}
	return (T) Float.valueOf(floatVal);
	} else if (type == Integer.TYPE) {
	return (T) Integer.valueOf(getIntRange(value, Integer.MIN_VALUE,
	Integer.MAX_VALUE, "int", msgPrefix));
	} else if (type == Long.TYPE) {
	if (!value.isWrappedJavaObject()) {
	throw new HostedModeException(msgPrefix + ": JS value of type "
	+ value.getTypeString() + ", expected Java long");
	}
	JavaLong javaLong = (JavaLong) value.getWrappedJavaObject();
	return (T) Long.valueOf(javaLong.longValue());
	} else if (type == Short.TYPE) {
	return (T) Short.valueOf((short) getIntRange(value, Short.MIN_VALUE,
	Short.MAX_VALUE, "short", msgPrefix));
	}
	}

	if (value.isNull() \|\| value.isUndefined()) {
	return null;
	}
	if (value.isWrappedJavaObject()) {
	return type.cast(value.getWrappedJavaObject());
	}
	if (value.isString()) {
	return type.cast(value.getString());
	}
	if (value.isJavaScriptObject()) {
	return type.cast(createJavaScriptObject(value, cl));
	}

	// Just don't know what do to with this.
	/*
	* TODO (amitmanjhi): does throwing a HostedModeException here and catching
	* a RuntimeException in user test
	* com.google.gwt.dev.jjs.test.HostedTest::testObjectReturns() make sense
	*/
	throw new IllegalArgumentException(msgPrefix + ": JS value of type "
	+ value.getTypeString() + ", expected "
	+ TypeInfo.getSourceRepresentation(type));
	}

	/**
	* Set the underlying value.
	*
	* @param value JsValue to set
	* @param type static type of the object
	* @param obj the object to store in the JS value
	*/
	public static void set(JsValue value, CompilingClassLoader cl, Class<?> type,
	Object obj) {
	if (type.isPrimitive()) {
	if (type == Boolean.TYPE) {
	value.setBoolean(((Boolean) obj).booleanValue());
	} else if (type == Byte.TYPE) {
	value.setInt(((Byte) obj).byteValue());
	} else if (type == Character.TYPE) {
	value.setInt(((Character) obj).charValue());
	} else if (type == Double.TYPE) {
	value.setDouble(((Double) obj).doubleValue());
	} else if (type == Float.TYPE) {
	value.setDouble(((Float) obj).floatValue());
	} else if (type == Integer.TYPE) {
	value.setInt(((Integer) obj).intValue());
	} else if (type == Long.TYPE) {
	long longVal = ((Long) obj).longValue();
	value.setWrappedJavaObject(cl, new JavaLong(longVal));
	} else if (type == Short.TYPE) {
	value.setInt(((Short) obj).shortValue());
	} else if (type == Void.TYPE) {
	value.setUndefined();
	} else {
	throw new HostedModeException("Cannot marshal primitive type " + type);
	}
	} else if (obj == null) {
	value.setNull();
	} else {
	// not a boxed primitive
	try {
	Class<?> jsoType = Class.forName(JSO_IMPL_CLASS, false, cl);
	if (jsoType == obj.getClass()) {
	JsValue jsObject = getUnderlyingObject(obj);
	value.setValue(jsObject);
	return;
	}
	} catch (ClassNotFoundException e) {
	// Ignore the exception, if we can't find the class then obviously we
	// don't have to worry about o being one
	}

	// Fall through case: Object.
	if (!type.isInstance(obj)) {
	throw new HostedModeException("object is of type "
	+ obj.getClass().getName() + ", expected " + type.getName());
	}
	if (obj instanceof String) {
	value.setString((String) obj);
	} else {
	value.setWrappedJavaObject(cl, obj);
	}
	}
	}

	private static int getIntRange(JsValue value, int low, int high,
	String typeName, String msgPrefix) {
	int intVal;
	if (value.isInt()) {
	intVal = value.getInt();
	if (intVal < low \|\| intVal > high) {
	throw new HostedModeException(msgPrefix + ": JS int value " + intVal
	+ " out of range for a " + typeName);
	}
	} else if (value.isNumber()) {
	double doubleVal = value.getNumber();
	if (doubleVal < low \|\| doubleVal > high) {
	throw new HostedModeException(msgPrefix + ": JS double value "
	+ doubleVal + " out of range for a " + typeName);
	}
	intVal = (int) doubleVal;
	if (intVal != doubleVal) {
	ModuleSpace.getLogger().log(TreeLogger.WARN,
	msgPrefix + ": Rounding double (" + doubleVal + ") to int for "
	+ typeName, null);
	}
	} else {
	throw new HostedModeException(msgPrefix + ": JS value of type "
	+ value.getTypeString() + ", expected " + typeName);
	}
	return intVal;
	}

	/**
	* Returns the underlying JsValue from a JavaScriptObject instance.
	*
	* The tricky part is that it is in a different ClassLoader so therefore can't
	* be specified directly. The type is specified as Object, and reflection is
	* used to retrieve the reference field.
	*
	* @param jso the instance of JavaScriptObject to retrieve the JsValue from.
	* @return the JsValue representing the JavaScript object
	*/
	private static JsValue getUnderlyingObject(Object jso) {
	Throwable caught;
	try {
	Field referenceField = jso.getClass().getField(HOSTED_MODE_REFERENCE);
	referenceField.setAccessible(true);
	return (JsValue) referenceField.get(jso);
	} catch (IllegalAccessException e) {
	caught = e;
	} catch (SecurityException e) {
	caught = e;
	} catch (NoSuchFieldException e) {
	caught = e;
	}
	throw new RuntimeException("Error reading " + HOSTED_MODE_REFERENCE, caught);
	}

	private JsValueGlue() {
	}
	}