// Copyright (C) 2010 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.google.gerrit.client.ui;
import com.google.gerrit.client.Gerrit;
import com.google.gwt.event.dom.client.BlurEvent;
import com.google.gwt.event.dom.client.BlurHandler;
import com.google.gwt.event.dom.client.FocusEvent;
import com.google.gwt.event.dom.client.FocusHandler;
import com.google.gwt.event.dom.client.KeyCodes;
import com.google.gwt.event.dom.client.KeyDownEvent;
import com.google.gwt.event.dom.client.KeyDownHandler;
import com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.user.client.ui.SuggestBox;
import com.google.gwt.user.client.ui.SuggestBox.DefaultSuggestionDisplay;
import com.google.gwt.user.client.ui.Widget;
import com.google.gwtexpui.globalkey.client.NpTextBox;
public class HintTextBox extends NpTextBox {
private HandlerRegistration hintFocusHandler;
private HandlerRegistration hintBlurHandler;
private HandlerRegistration keyDownHandler;
private String hintText;
private String hintStyleName = Gerrit.RESOURCES.css().inputFieldTypeHint();
private String prevText;
private boolean hintOn;
private boolean isFocused;
public String getText() {
if (hintOn) {
return "";
}
return super.getText();
}
public void setText(String text) {
focusHint();
super.setText(text);
prevText = text;
if (! isFocused) {
blurHint();
}
}
public String getHintText() {
return hintText;
}
public void setHintText(String text) {
if (text == null) {
if (hintText == null) { // was not set, still not set, no change.
return;
}
// Clearing a previously set Hint
hintFocusHandler.removeHandler();
hintFocusHandler = null;
hintBlurHandler.removeHandler();
hintBlurHandler = null;
keyDownHandler.removeHandler();
keyDownHandler = null;
hintText = null;
focusHint();
return;
}
// Setting Hints
if (hintText == null) { // first time (was not already set)
hintText = text;
hintFocusHandler = addFocusHandler(new FocusHandler() {
@Override
public void onFocus(FocusEvent event) {
focusHint();
prevText = getText();
isFocused = true;
}
});
hintBlurHandler = addBlurHandler(new BlurHandler() {
@Override
public void onBlur(BlurEvent event) {
blurHint();
isFocused = false;
}
});
/*
* There seems to be a strange bug (at least on firefox 3.5.9 ubuntu) with
* the textbox under the following circumstances:
* 1) The field is not focused with BText in it.
* 2) The field receives focus and a focus listener changes the text to FText
* 3) The ESC key is pressed and the value of the field has not changed
* (ever) from FText
* 4) BUG: The text value gets reset to BText!
*
* A counter to this bug seems to be to force setFocus(false) on ESC.
*/
/* Chrome does not create a KeyPressEvent on ESC, so use KeyDownEvents */
keyDownHandler = addKeyDownHandler(new KeyDownHandler() {
@Override
public void onKeyDown(final KeyDownEvent event) {
onKey(event.getNativeKeyCode());
}
});
} else { // Changing an already set Hint
focusHint();
hintText = text;
}
if (! isFocused) {
blurHint();
}
}
private void onKey(int key) {
if (key == KeyCodes.KEY_ESCAPE) {
setText(prevText);
Widget p = getParent();
if (p instanceof SuggestBox) {
// Since the text was changed, ensure that the SuggestBox is
// aware of this change so that it will refresh properly on
// the next keystroke. Without this, if the first keystroke
// recreates the same string as before ESC was pressed, the
// SuggestBox will think that the string has not changed, and
// it will not yet provide any Suggestions.
((SuggestBox)p).showSuggestionList();
// The suggestion list lingers if we don't hide it.
((DefaultSuggestionDisplay) ((SuggestBox) p).getSuggestionDisplay())
.hideSuggestions();
}
setFocus(false);
}
}
public void setHintStyleName(String styleName) {
if (hintStyleName != null && hintOn) {
removeStyleName(hintStyleName);
}
hintStyleName = styleName;
if (styleName != null && hintOn) {
addStyleName(styleName);
}
}
public String getHintStyleName() {
return hintStyleName;
}
protected void blurHint() {
if (! hintOn && getHintText() != null && "".equals(super.getText())) {
hintOn = true;
super.setText(getHintText());
if (getHintStyleName() != null) {
addStyleName(getHintStyleName());
}
}
}
protected void focusHint() {
if (hintOn) {
super.setText("");
if (getHintStyleName() != null) {
removeStyleName(getHintStyleName());
}
hintOn = false;
}
}
public void setFocus(boolean focus) {
super.setFocus(focus);
if (focus != isFocused) {
if (focus) {
focusHint();
} else {
blurHint();
}
}
isFocused = focus;
}
}