com.tractionsoftware.gwt.user.client.ui.AutoSizingTextArea.java Source code

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Here is the source code for com.tractionsoftware.gwt.user.client.ui.AutoSizingTextArea.java

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/*
 * Copyright 2010 Traction Software, 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 com.tractionsoftware.gwt.user.client.ui;

import com.google.gwt.core.client.Scheduler;
import com.google.gwt.core.client.Scheduler.ScheduledCommand;
import com.google.gwt.dom.client.Element;
import com.google.gwt.event.logical.shared.ResizeEvent;
import com.google.gwt.event.logical.shared.ResizeHandler;
import com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.ui.TextArea;
import com.tractionsoftware.gwt.user.client.util.MiscUtils;

/**
 * This attaches to an input, listening for KeyDown/KeyUp, and
 * automatically resizing the text area. It does this using an
 * invisible textarea that matches the text of the input.
 */
public class AutoSizingTextArea extends AutoSizingBase<TextAreaWithSelection, TextArea> implements ResizeHandler {

    protected int divExtra = 0;
    protected HandlerRegistration resizeRegistration = null;

    public AutoSizingTextArea() {
        this(new TextAreaWithSelection());
    }

    private AutoSizingTextArea(TextAreaWithSelection box) {
        super(box, new TextArea());
    }

    public AutoSizingTextArea(TextAreaWithSelection box, int minSize, int maxSize) {
        super(box, new TextArea());
        setMinSize(minSize);
        setMaxSize(maxSize);
    }

    @Override
    protected void onLoad() {
        Element boxElement = box.getElement();

        int lineHeight = MiscUtils.getComputedStyleInt(boxElement, "lineHeight");
        setExtraSize(lineHeight);

        setMinFromCss("minHeight");
        setMaxFromCss("maxHeight");

        // we also need to make sure the widths are the same.
        matchStyles("width");

        // don't let the shadow have any size
        shadow.setHeight("0");

        divExtra = 0;
        divExtra += MiscUtils.getComputedStyleInt(boxElement, "paddingTop");
        divExtra += MiscUtils.getComputedStyleInt(boxElement, "paddingBottom");

        resizeRegistration = Window.addResizeHandler(this);

        super.onLoad();
    }

    @Override
    protected void onUnload() {
        // fix leak reported in issue #4
        if (resizeRegistration != null) {
            resizeRegistration.removeHandler();
            resizeRegistration = null;
        }

        super.onUnload();
    }

    @Override
    public void onResize(ResizeEvent event) {
        matchStyles("width");
        adjustSize();
    }

    @Override
    public void setHeight(int height) {
        div.setHeight(divExtra + height + "px");
        box.setHeight(height + "px");
    }

    /**
     * Returns the size of the shadow element
     */
    @Override
    public int getShadowSize() {
        Element shadowElement = shadow.getElement();
        shadowElement.setScrollTop(10000);
        return shadowElement.getScrollTop();
    }

    /**
     * @param text the text that should be set on the shadow to
     * determine the appropriate size of the widget
     */
    @Override
    public void setShadowText(String text) {
        shadow.setValue(text);
    }

    /**
     * @param size will take into account minSize, maxSize, and
     * extraSize. the implementation should just call setWidth or
     * setHeight as appropriate.
     */
    @Override
    public void setSize(int size) {
        setHeight(size);
        if (size == maxSize) {
            box.getElement().getStyle().setProperty("overflow", "auto");
        }
    }

    @Override
    public void setText(String text) {
        box.setText(text);
        Scheduler.get().scheduleDeferred(new ScheduledCommand() {
            @Override
            public void execute() {
                sync();
            }
        });
    }

}