Added support to clear an editable element (i.e. text field)

Added unit test

app/android.js

@@ -370,7 +370,7 @@ Android.prototype.complexTap = function(tapCount, touchCount, duration, x, y, el
 };
 
 Android.prototype.clear = function(elementId, cb) {
-  cb(new NotYetImplementedError(), null);
+  this.proxy(["element:clear", {elementId: elementId}], cb);
 };
 
 Android.prototype.submit = function(elementId, cb) {

test/functional/apidemos/keyboard.js

@@ -28,4 +28,33 @@ describeWd('text boxes', function(h) {
       });
     });
   });
+  it('should be able to clear editText', function(done) {
+    h.driver.elementByTagName('editText', function(err, el) {
+      should.not.exist(err);
+      // get the text
+      el.text(function(err, text) {
+        should.not.exist(err);
+        text.should.equal("");
+        // set the text
+        el.sendKeys(testText, function(err) {
+          should.not.exist(err);
+          // make sure the text is actuall in the edittext
+          el.text(function(err, text) {
+            should.not.exist(err);
+            text.should.equal(testText);
+            // now clear it
+            el.clear(function(err) {
+              should.not.exist(err);
+              // make sure that it's empty
+              el.text(function(err, text) {
+                should.not.exist(err);
+                text.should.equal("");
+                done();
+              });
+            });
+          });
+        });
+      });
+    });
+  });
 });

uiautomator/bootstrap/src/io/appium/android/bootstrap/AndroidCommandExecutor.java

@@ -1,6 +1,7 @@
 package io.appium.android.bootstrap;
 
 import io.appium.android.bootstrap.exceptions.AndroidCommandException;
+import io.appium.android.bootstrap.handler.Clear;
 import io.appium.android.bootstrap.handler.Click;
 import io.appium.android.bootstrap.handler.Find;
 import io.appium.android.bootstrap.handler.Flick;
@@ -25,6 +26,7 @@ class AndroidCommandExecutor {
   private static HashMap<String, CommandHandler> map = new HashMap<String, CommandHandler>();
 
   static {
+    map.put("clear", new Clear());
     map.put("orientation", new Orientation());
     map.put("swipe", new Swipe());
     map.put("flick", new Flick());

uiautomator/bootstrap/src/io/appium/android/bootstrap/AndroidElement.java

@@ -27,6 +27,10 @@ public class AndroidElement {
     el = uiObj;
   }
 
+  public void clearText() throws UiObjectNotFoundException {
+    el.clearTextField();
+  }
+
   public boolean click() throws UiObjectNotFoundException {
     return el.click();
   }

uiautomator/bootstrap/src/io/appium/android/bootstrap/handler/Clear.java

@@ -0,0 +1,52 @@
+package io.appium.android.bootstrap.handler;
+
+import io.appium.android.bootstrap.AndroidCommand;
+import io.appium.android.bootstrap.AndroidCommandResult;
+import io.appium.android.bootstrap.AndroidElement;
+import io.appium.android.bootstrap.CommandHandler;
+import io.appium.android.bootstrap.WDStatus;
+import io.appium.android.bootstrap.exceptions.ElementNotInHashException;
+
+import org.json.JSONException;
+
+import com.android.uiautomator.core.UiObjectNotFoundException;
+
+/**
+ * This handler is used to clear elements in the Android UI.
+ * 
+ * Based on the element Id, clear that element.
+ * 
+ * @author <a href="https://github.com/xuru">xuru</a>
+ * 
+ */
+public class Clear extends CommandHandler {
+
+  /*
+   * @param command The {@link AndroidCommand}
+   * 
+   * @return {@link AndroidCommandResult}
+   * 
+   * @throws JSONException
+   * 
+   * @see io.appium.android.bootstrap.CommandHandler#execute(io.appium.android.
+   * bootstrap.AndroidCommand)
+   */
+  @Override
+  public AndroidCommandResult execute(final AndroidCommand command)
+      throws JSONException {
+    if (command.isElementCommand()) {
+      try {
+        final AndroidElement el = command.getElement();
+        el.clearText();
+        return getSuccessResult(true);
+      } catch (final UiObjectNotFoundException e) {
+        return new AndroidCommandResult(WDStatus.NO_SUCH_ELEMENT,
+            e.getMessage());
+      } catch (final ElementNotInHashException e) {
+        return new AndroidCommandResult(WDStatus.NO_SUCH_ELEMENT,
+            e.getMessage());
+      }
+    }
+    return getErrorResult("Unknown error clearing text");
+  }
+}