Patch for #3754 with slightly modified javadoc

svn changeset:9988/svn branch:6.2

diff --git a/src/com/vaadin/data/util/TextFileProperty.java b/src/com/vaadin/data/util/TextFileProperty.java
new file mode 100644 (file)
index 0000000..9d1c8b8
--- /dev/null
+++ b/src/com/vaadin/data/util/TextFileProperty.java
@@ -0,0 +1,227 @@
+/* \r
+@ITMillApache2LicenseForJavaFiles@\r
+ */\r
+\r
+package com.vaadin.data.util;\r
+\r
+import java.io.BufferedReader;\r
+import java.io.BufferedWriter;\r
+import java.io.File;\r
+import java.io.FileInputStream;\r
+import java.io.FileNotFoundException;\r
+import java.io.FileOutputStream;\r
+import java.io.IOException;\r
+import java.io.InputStreamReader;\r
+import java.io.OutputStreamWriter;\r
+import java.nio.charset.Charset;\r
+import java.util.LinkedList;\r
+\r
+import com.vaadin.data.Property;\r
+\r
+/**\r
+ * Property implementation for wrapping a text file.\r
+ * \r
+ * Supports reading and writing of a File from/to String. ValueChangeNotifiers\r
+ * are supported, but only fire when setValue(Object) is explicitly called.\r
+ */\r
+@SuppressWarnings("serial")\r
+public class TextFileProperty implements Property, Property.ValueChangeNotifier {\r
+\r
+    private File file;\r
+    private boolean readonly;\r
+    private Charset charset = null;\r
+    private LinkedList<Property.ValueChangeListener> valueChangeListeners = null;\r
+\r
+    /**\r
+     * Wrap given file with property interface.\r
+     * \r
+     * Setting the file to null works, but getValue() will return null.\r
+     * \r
+     * @param file\r
+     *            File to be wrapped.\r
+     */\r
+    public TextFileProperty(File file) {\r
+        this.file = file;\r
+    }\r
+\r
+    /**\r
+     * Wrap the given file with the property interface and specify character\r
+     * set.\r
+     * \r
+     * Setting the file to null works, but getValue() will return null.\r
+     * \r
+     * @param file\r
+     *            File to be wrapped.\r
+     * @param charset\r
+     *            Charset to be used for reading and writing the file.\r
+     */\r
+    public TextFileProperty(File file, Charset charset) {\r
+        this.file = file;\r
+        this.charset = charset;\r
+    }\r
+\r
+    /*\r
+     * (non-Javadoc)\r
+     * \r
+     * @see com.vaadin.data.Property#getType()\r
+     */\r
+    public Class<?> getType() {\r
+        return String.class;\r
+    }\r
+\r
+    /*\r
+     * (non-Javadoc)\r
+     * \r
+     * @see com.vaadin.data.Property#getValue()\r
+     */\r
+    public Object getValue() {\r
+        if (file == null) {\r
+            return null;\r
+        }\r
+        try {\r
+            FileInputStream fis = new FileInputStream(file);\r
+            InputStreamReader isr = charset == null ? new InputStreamReader(fis)\r
+                    : new InputStreamReader(fis, charset);\r
+            BufferedReader r = new BufferedReader(isr);\r
+            StringBuilder b = new StringBuilder();\r
+            char buf[] = new char[8 * 1024];\r
+            int len;\r
+            while ((len = r.read(buf)) != -1) {\r
+                b.append(buf, 0, len);\r
+            }\r
+            r.close();\r
+            isr.close();\r
+            fis.close();\r
+            return b.toString();\r
+        } catch (FileNotFoundException e) {\r
+            return null;\r
+        } catch (IOException e) {\r
+            throw new RuntimeException(e);\r
+        }\r
+    }\r
+\r
+    /*\r
+     * (non-Javadoc)\r
+     * \r
+     * @see com.vaadin.data.Property#isReadOnly()\r
+     */\r
+    public boolean isReadOnly() {\r
+        return file == null || readonly || !file.canWrite();\r
+    }\r
+\r
+    /*\r
+     * (non-Javadoc)\r
+     * \r
+     * @see com.vaadin.data.Property#setReadOnly(boolean)\r
+     */\r
+    public void setReadOnly(boolean newStatus) {\r
+        readonly = newStatus;\r
+    }\r
+\r
+    /*\r
+     * (non-Javadoc)\r
+     * \r
+     * @see com.vaadin.data.Property#setValue(java.lang.Object)\r
+     */\r
+    public void setValue(Object newValue) throws ReadOnlyException {\r
+        if (isReadOnly()) {\r
+            throw new ReadOnlyException();\r
+        }\r
+        if (file == null) {\r
+            return;\r
+        }\r
+\r
+        try {\r
+            FileOutputStream fos = new FileOutputStream(file);\r
+            OutputStreamWriter osw = charset == null ? new OutputStreamWriter(\r
+                    fos) : new OutputStreamWriter(fos, charset);\r
+            BufferedWriter w = new BufferedWriter(osw);\r
+            w.append(newValue.toString());\r
+            w.flush();\r
+            w.close();\r
+            osw.close();\r
+            fos.close();\r
+            fireValueChange();\r
+        } catch (IOException e) {\r
+            throw new RuntimeException(e);\r
+        }\r
+    }\r
+\r
+    /*\r
+     * (non-Javadoc)\r
+     * \r
+     * @see java.lang.Object#toString()\r
+     */\r
+    @Override\r
+    public String toString() {\r
+        return (String) getValue();\r
+    }\r
+\r
+    /* Events */\r
+\r
+    /**\r
+     * An <code>Event</code> object specifying the TextFileProperty whose value\r
+     * has changed.\r
+     */\r
+    private class ValueChangeEvent extends java.util.EventObject implements\r
+            Property.ValueChangeEvent {\r
+\r
+        /**\r
+         * Constructs a new value change event for this object.\r
+         * \r
+         * @param source\r
+         *            the source object of the event.\r
+         */\r
+        protected ValueChangeEvent(TextFileProperty source) {\r
+            super(source);\r
+        }\r
+\r
+        /**\r
+         * Gets the Property whose read-only state has changed.\r
+         * \r
+         * @return source the Property of the event.\r
+         */\r
+        public Property getProperty() {\r
+            return (Property) getSource();\r
+        }\r
+    }\r
+\r
+    /**\r
+     * Removes a previously registered value change listener.\r
+     * \r
+     * @param listener\r
+     *            the listener to be removed.\r
+     */\r
+    public void removeListener(Property.ValueChangeListener listener) {\r
+        if (valueChangeListeners != null) {\r
+            valueChangeListeners.remove(listener);\r
+        }\r
+    }\r
+\r
+    /**\r
+     * Registers a new value change listener for this TextFileProperty.\r
+     * \r
+     * @param listener\r
+     *            the new Listener to be registered\r
+     */\r
+    public void addListener(Property.ValueChangeListener listener) {\r
+        if (valueChangeListeners == null) {\r
+            valueChangeListeners = new LinkedList();\r
+        }\r
+        valueChangeListeners.add(listener);\r
+    }\r
+\r
+    /**\r
+     * Sends a value change event to all registered listeners.\r
+     */\r
+    private void fireValueChange() {\r
+        if (valueChangeListeners != null) {\r
+            final Object[] l = valueChangeListeners.toArray();\r
+            final ValueChangeEvent event = new ValueChangeEvent(this);\r
+            for (int i = 0; i < l.length; i++) {\r
+                ((ValueChangeListener) l[i]).valueChange(event);\r
+            }\r
+        }\r
+    }\r
+\r
+}\r