Issue #16 - TextDecoder support

gwt-typedarrays-gwt2-tests/src/test/java/org/gwtproject/typedarrays/shared/DataViewTest.java

@@ -71,6 +71,17 @@ public void testBasic() {
     assertEquals(0x80042001, view.getInt32(0, true));
   }
 
+  public void testDecoder() {
+    Int8Array array = TypedArrays.createInt8Array(9);
+    array.set(new int[] {'A', 'L', 'E', 'X', 'A', 'N', 'D', 'E', 'R'});
+
+    TextDecoder textDecoder = TypedArrays.createTextDecoder("utf-8");
+    assertEquals("ALEXANDER", textDecoder.decode(array));
+
+    DataView view = TypedArrays.createDataView(array.buffer(), 1, 3);
+    assertEquals("LEX", textDecoder.decode(view));
+  }
+
   //  public void testFoo() {
   //    System.out.println((short)0x80);
   //    System.out.println((byte)((short)0x80));

gwt-typedarrays/src/main/java/org/gwtproject/typedarrays/client/NativeImpl.java

@@ -25,6 +25,7 @@
 import org.gwtproject.typedarrays.shared.Int16Array;
 import org.gwtproject.typedarrays.shared.Int32Array;
 import org.gwtproject.typedarrays.shared.Int8Array;
+import org.gwtproject.typedarrays.shared.TextDecoder;
 import org.gwtproject.typedarrays.shared.TypedArrays;
 import org.gwtproject.typedarrays.shared.Uint16Array;
 import org.gwtproject.typedarrays.shared.Uint32Array;
@@ -345,4 +346,9 @@ protected boolean checkUint8ClampedArraySupport() {
   protected boolean runtimeSupportCheck() {
     return Js.<JsPropertyMap<Object>>uncheckedCast(DomGlobal.window).has("ArrayBuffer");
   }
+
+  @Override
+  protected TextDecoder createDecoder(String label) {
+    return new TextDecoderNative(label);
+  }
 }

gwt-typedarrays/src/main/java/org/gwtproject/typedarrays/client/TextDecoderNative.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2012 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 org.gwtproject.typedarrays.client;
+
+import jsinterop.annotations.JsPackage;
+import jsinterop.annotations.JsType;
+import org.gwtproject.typedarrays.shared.ArrayBuffer;
+import org.gwtproject.typedarrays.shared.ArrayBufferView;
+import org.gwtproject.typedarrays.shared.TextDecoder;
+
+@JsType(isNative = true, name = "TextDecoder", namespace = JsPackage.GLOBAL)
+public class TextDecoderNative implements TextDecoder {
+
+  public TextDecoderNative(String label) {}
+
+  @Override
+  public native String decode(ArrayBuffer buffer);
+
+  @Override
+  public native String decode(ArrayBufferView bufferView);
+}

gwt-typedarrays/src/main/java/org/gwtproject/typedarrays/server/ArrayBufferImpl.java

@@ -29,7 +29,7 @@ public class ArrayBufferImpl implements ArrayBuffer {
 
   private final Object lock = new Object();
 
-  private final ByteBuffer buf;
+  protected final ByteBuffer buf;
 
   /** @param length the size in bytes of the new array buffer instance */
   public ArrayBufferImpl(int length) {

gwt-typedarrays/src/main/java/org/gwtproject/typedarrays/server/JavaImpl.java

@@ -24,6 +24,7 @@
 import org.gwtproject.typedarrays.shared.Int16Array;
 import org.gwtproject.typedarrays.shared.Int32Array;
 import org.gwtproject.typedarrays.shared.Int8Array;
+import org.gwtproject.typedarrays.shared.TextDecoder;
 import org.gwtproject.typedarrays.shared.TypedArrays;
 import org.gwtproject.typedarrays.shared.Uint16Array;
 import org.gwtproject.typedarrays.shared.Uint32Array;
@@ -365,6 +366,12 @@ public Uint8ClampedArray createUint8ClampedArray(short[] array) {
     return result;
   }
 
+  @GwtIncompatible
+  @Override
+  protected TextDecoder createDecoder(String label) {
+    return new TextDecoderImpl(label);
+  }
+
   @GwtIncompatible
   @Override
   protected boolean runtimeSupportCheck() {

gwt-typedarrays/src/main/java/org/gwtproject/typedarrays/server/TextDecoderImpl.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2012 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 org.gwtproject.typedarrays.server;
+
+import java.nio.ByteBuffer;
+import java.nio.charset.CharacterCodingException;
+import java.nio.charset.CharsetDecoder;
+import java.nio.charset.StandardCharsets;
+import org.gwtproject.core.shared.GwtIncompatible;
+import org.gwtproject.typedarrays.shared.ArrayBuffer;
+import org.gwtproject.typedarrays.shared.ArrayBufferView;
+import org.gwtproject.typedarrays.shared.TextDecoder;
+
+@GwtIncompatible
+public class TextDecoderImpl implements TextDecoder {
+
+  private final CharsetDecoder decoder;
+
+  public TextDecoderImpl(CharsetDecoder decoder) {
+    this.decoder = decoder;
+  }
+
+  public TextDecoderImpl(String label) {
+    if (label.equals("utf-8")) {
+      this.decoder = StandardCharsets.UTF_8.newDecoder();
+    } else {
+      throw new RuntimeException("Label: " + label);
+    }
+  }
+
+  @Override
+  public String decode(ArrayBuffer buffer) {
+    ArrayBufferImpl impl = (ArrayBufferImpl) buffer;
+    try {
+      return decoder.decode(impl.buf).toString();
+    } catch (CharacterCodingException e) {
+      throw new RuntimeException(e);
+    }
+  }
+
+  @Override
+  public String decode(ArrayBufferView bufferView) {
+    ArrayBufferViewImpl viewImpl = (ArrayBufferViewImpl) bufferView;
+    ByteBuffer buf = viewImpl.arrayBuf.buf.slice();
+    buf.position(viewImpl.byteOffset);
+    buf.limit(viewImpl.byteOffset + viewImpl.byteLength);
+    try {
+      return decoder.decode(buf).toString();
+    } catch (CharacterCodingException e) {
+      throw new RuntimeException(e);
+    }
+  }
+}

gwt-typedarrays/src/main/java/org/gwtproject/typedarrays/shared/TextDecoder.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2012 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 org.gwtproject.typedarrays.shared;
+
+import jsinterop.annotations.JsPackage;
+import jsinterop.annotations.JsType;
+
+/**
+ * The TextDecoder interface represents a decoder for a specific text encoding, such as UTF-8,
+ * ISO-8859-2, KOI8-R, GBK, etc. A decoder takes a stream of bytes as input and emits a stream of
+ * code points.
+ */
+@JsType(isNative = true, name = "TextDecoder", namespace = JsPackage.GLOBAL)
+public interface TextDecoder {
+
+  /**
+   * The TextDecoder.prototype.decode() method returns a String containing the text in {@code
+   * buffer}, decoded with the specific method for this TextDecoder object.
+   */
+  String decode(ArrayBuffer buffer);
+
+  /**
+   * The TextDecoder.prototype.decode() method returns a String containing the text in {@code
+   * buffer}, decoded with the specific method for this TextDecoder object.
+   */
+  String decode(ArrayBufferView bufferView);
+}

gwt-typedarrays/src/main/java/org/gwtproject/typedarrays/shared/TypedArrays.java

@@ -179,6 +179,8 @@ protected boolean mightBeSupported() {
      * @return true if the current environment actually does support typed arrays
      */
     protected abstract boolean runtimeSupportCheck();
+
+    protected abstract TextDecoder createDecoder(String label);
   }
   // CHECKSTYLE_ON
 
@@ -664,6 +666,18 @@ public static Uint8ClampedArray createUint8ClampedArray(int length) {
     return Instance.impl.createUint8ClampedArray(length);
   }
 
+  /**
+   * Creates a new instance of {@link TextDecoder}.
+   *
+   * @param label the "label" of the encoder, for example "utf-8". See <a
+   *     href="https://developer.mozilla.org/en-US/docs/Web/API/Encoding_API/Encodings">all
+   *     encodings</a>.
+   * @return a {@link TextDecoder} instance.
+   */
+  public static TextDecoder createTextDecoder(String label) {
+    return Instance.impl.createDecoder(label);
+  }
+
   /**
    * Check if the current environment supports typed arrays. Behavior of the various {@code
    * createXXX} methods is undefined if this method returns {@code false}, but will typically throw