/*
* Copyright 2011 Vaadin Ltd.
*
* 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.vaadin.terminal.gwt.client.ui;
import com.google.gwt.core.client.Scheduler;
import com.google.gwt.event.dom.client.ChangeEvent;
import com.google.gwt.event.dom.client.ChangeHandler;
import com.google.gwt.event.dom.client.KeyDownEvent;
import com.google.gwt.event.dom.client.KeyUpEvent;
import com.google.gwt.event.dom.client.KeyUpHandler;
import com.google.gwt.user.client.Command;
import com.google.gwt.user.client.DOM;
import com.google.gwt.user.client.Element;
import com.google.gwt.user.client.Event;
import com.vaadin.terminal.gwt.client.ApplicationConnection;
import com.vaadin.terminal.gwt.client.BrowserInfo;
import com.vaadin.terminal.gwt.client.UIDL;
/**
* This class represents a multiline textfield (textarea).
*
* TODO consider replacing this with a RichTextArea based implementation. IE
* does not support CSS height for textareas in Strict mode :-(
*
* @author Vaadin Ltd.
*
*/
public class VTextArea extends VTextField {
public static final String CLASSNAME = "v-textarea";
private MaxLengthHandler maxLengthHandler = new MaxLengthHandler();
private boolean browserSupportsMaxLengthAttribute = browserSupportsMaxLengthAttribute();
public VTextArea() {
super(DOM.createTextArea());
setStyleName(CLASSNAME);
if (!browserSupportsMaxLengthAttribute) {
addKeyUpHandler(maxLengthHandler);
addChangeHandler(maxLengthHandler);
sinkEvents(Event.ONPASTE);
}
}
@Override
public void updateFromUIDL(UIDL uidl, ApplicationConnection client) {
// Call parent renderer explicitly
super.updateFromUIDL(uidl, client);
if (uidl.hasAttribute("rows")) {
setRows(uidl.getIntAttribute("rows"));
}
}
@Override
public void setSelectionRange(int pos, int length) {
super.setSelectionRange(pos, length);
final String value = getValue();
/*
* Align position to index inside string value
*/
int index = pos;
if (index < 0) {
index = 0;
}
if (index > value.length()) {
index = value.length();
}
// Get pixels count required to scroll textarea vertically
int scrollTop = getScrollTop(value, index);
int scrollLeft = -1;
/*
* Check if textarea has wrap attribute set to "off". In the latter case
* horizontal scroll is also required.
*/
if (!isWordwrap()) {
// Get pixels count required to scroll textarea horizontally
scrollLeft = getScrollLeft(value, index);
}
// Set back original text if previous methods calls changed it
if (!isWordwrap() || index < value.length()) {
setValue(value, false);
}
/*
* Call original method to set cursor position. In most browsers it
* doesn't lead to scrolling.
*/
super.setSelectionRange(pos, length);
/*
* Align vertical scroll to middle of textarea view (height) if
* scrolling is reqiured at all.
*/
if (scrollTop > 0) {
scrollTop += getElement().getClientHeight() / 2;
}
/*
* Align horizontal scroll to middle of textarea view (widht) if
* scrolling is reqiured at all.
*/
if (scrollLeft > 0) {
scrollLeft += getElement().getClientWidth() / 2;
}
/*
* Scroll if computed scrollTop is greater than scroll after cursor
* setting
*/
if (getElement().getScrollTop() < scrollTop) {
getElement().setScrollTop(scrollTop);
}
/*
* Scroll if computed scrollLeft is greater than scroll after cursor
* setting
*/
if (getElement().getScrollLeft() < scrollLeft) {
getElement().setScrollLeft(scrollLeft);
}
}
/*
* Get horizontal scroll value required to get position visible. Method is
* called only when text wrapping is off. There is need to scroll
* horizontally in case words are wrapped.
*/
private int getScrollLeft(String value, int index) {
String beginning = value.substring(0, index);
// Compute beginning of the current line
int begin = beginning.lastIndexOf('\n');
String line = value.substring(begin + 1);
index = index - begin - 1;
if (index < line.length()) {
index++;
}
line = line.substring(0, index);
/*
* Now <code>line</code> contains current line up to index position
*/
setValue(line.trim(), false); // Set this line to the textarea.
/*
* Scroll textarea up to the end of the line (maximum possible
* horizontal scrolling value). Now the end line becomes visible.
*/
getElement().setScrollLeft(getElement().getScrollWidth());
// Return resulting horizontal scrolling value.
return getElement().getScrollLeft();
}
/*
* Get vertical scroll value required to get position visible
*/
private int getScrollTop(String value, int index) {
/*
* Trim text after position and set this trimmed text if index is not
* very end.
*/
if (index < value.length()) {
String beginning = value.substring(0, index);
setValue(beginning, false);
}
/*
* Now textarea contains trimmed text and could be scrolled up to the
* top. Scroll it to maximum possible value to get end of the text
* visible.
*/
getElement().setScrollTop(getElement().getScrollHeight());
// Return resulting vertical scrolling value.
return getElement().getScrollTop();
}
private class MaxLengthHandler implements KeyUpHandler, ChangeHandler {
public void onKeyUp(KeyUpEvent event) {
enforceMaxLength();
}
public void onPaste(Event event) {
enforceMaxLength();
}
public void onChange(ChangeEvent event) {
// Opera does not support paste events so this enforces max length
// for Opera.
enforceMaxLength();
}
}
protected void enforceMaxLength() {
if (getMaxLength() >= 0) {
Scheduler.get().scheduleDeferred(new Command() {
public void execute() {
if (getText().length() > getMaxLength()) {
setText(getText().substring(0, getMaxLength()));
}
}
});
}
}
protected boolean browserSupportsMaxLengthAttribute() {
BrowserInfo info = BrowserInfo.get();
if (info.isFirefox() && info.isBrowserVersionNewerOrEqual(4, 0)) {
return true;
}
if (info.isSafari() && info.isBrowserVersionNewerOrEqual(5, 0)) {
return true;
}
if (info.isIE() && info.isBrowserVersionNewerOrEqual(10, 0)) {
return true;
}
if (info.isAndroid() && info.isBrowserVersionNewerOrEqual(2, 3)) {
return true;
}
return false;
}
@Override
protected void updateMaxLength(int maxLength) {
if (browserSupportsMaxLengthAttribute) {
super.updateMaxLength(maxLength);
} else {
// Events handled by MaxLengthHandler. This call enforces max length
// when the max length value has changed
enforceMaxLength();
}
}
@Override
public void onBrowserEvent(Event event) {
super.onBrowserEvent(event);
if (event.getTypeInt() == Event.ONPASTE) {
maxLengthHandler.onPaste(event);
}
}
public void setRows(int rows) {
setRows(getElement(), rows);
}
private native void setRows(Element e, int r)
/*-{
try {
if(e.tagName.toLowerCase() == "textarea")
e.rows = r;
} catch (e) {}
}-*/;
@Override
public int getCursorPos() {
// This is needed so that TextBoxImplIE6 is used to return the correct
// position for old Internet Explorer versions where it has to be
// detected in a different way.
return getImpl().getTextAreaCursorPos(getElement());
}
@Override
public void onKeyDown(KeyDownEvent event) {
// Overridden to avoid submitting TextArea value on enter in IE. This is
// another reason why widgets should inherit a common abstract
// class instead of directly each other.
}
}