com.kotcrab.vis.ui.widget.ScrollableTextArea.java Source code

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Here is the source code for com.kotcrab.vis.ui.widget.ScrollableTextArea.java

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/*
 * Copyright 2014-2016 See AUTHORS file.
 *
 * 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.kotcrab.vis.ui.widget;

import com.badlogic.gdx.math.Rectangle;
import com.badlogic.gdx.scenes.scene2d.Group;
import com.badlogic.gdx.scenes.scene2d.InputEvent;
import com.badlogic.gdx.scenes.scene2d.InputListener;
import com.badlogic.gdx.scenes.scene2d.ui.ScrollPane;
import com.badlogic.gdx.scenes.scene2d.utils.Cullable;

/**
 * Custom {@link VisTextArea} supporting embedding in scroll pane by calculating required space needed for current text.
 * <p>
 * Warning: By default this can only support vertical scrolling. Scrolling in X direction MUST be disabled. It is NOT possible
 * to use vertical scrolling without child class properly implementing {@link #getPrefWidth()} and disabling soft wraps.
 * Example of such class is {@link HighlightTextArea}.
 * <p>
 * For best scroll pane settings you should create scroll pane using {@link #createCompatibleScrollPane()}.
 * @author Kotcrab
 * @since 1.1.2
 */
public class ScrollableTextArea extends VisTextArea implements Cullable {
    private Rectangle cullingArea;

    public ScrollableTextArea(String text) {
        super(text, "textArea");
    }

    public ScrollableTextArea(String text, String styleName) {
        super(text, styleName);
    }

    public ScrollableTextArea(String text, VisTextFieldStyle style) {
        super(text, style);
    }

    @Override
    protected InputListener createInputListener() {
        return new ScrollTextAreaListener();
    }

    @Override
    protected void setParent(Group parent) {
        super.setParent(parent);
        if (parent instanceof ScrollPane) {
            calculateOffsets();
        }
    }

    private void updateScrollPosition() {
        if (cullingArea == null || getParent() instanceof ScrollPane == false)
            return;
        ScrollPane scrollPane = (ScrollPane) getParent();

        if (cullingArea.contains(getCursorX(), cullingArea.y) == false) {
            scrollPane.setScrollPercentX(getCursorX() / getWidth());
        }

        if (cullingArea.contains(cullingArea.x, (getHeight() - getCursorY())) == false) {
            scrollPane.setScrollPercentY(getCursorY() / getHeight());
        }
    }

    @Override
    public void setCullingArea(Rectangle cullingArea) {
        this.cullingArea = cullingArea;
    }

    /**
     * Creates scroll pane for this scrolling text area with best possible default settings. Note that text area
     * can belong to only one scroll pane, calling this multiple times will break previously created scroll pane.
     * The scroll pane should be embedded in container with fixed size or optionally grow property.
     * @return newly created scroll pane which can be added directly to container.
     */
    public ScrollPane createCompatibleScrollPane() {
        VisScrollPane scrollPane = new VisScrollPane(this);
        scrollPane.setOverscroll(false, false);
        scrollPane.setFlickScroll(false);
        scrollPane.setFadeScrollBars(false);
        scrollPane.setScrollbarsOnTop(true);
        scrollPane.setScrollingDisabled(true, false);
        return scrollPane;
    }

    @Override
    protected void sizeChanged() {
        super.sizeChanged();
        linesShowing = 1000000000; //aka a lot, forces text area not to use its stupid 'scrolling'
    }

    @Override
    public float getPrefHeight() {
        return getLines() * style.font.getLineHeight();
    }

    @Override
    public void setText(String str) {
        super.setText(str);
        if (programmaticChangeEvents == false) { //changeText WILL NOT be called when programmaticChangeEvents are disabled
            updateScrollLayout();
        }
    }

    @Override
    boolean changeText(String oldText, String newText) {
        boolean changed = super.changeText(oldText, newText);
        updateScrollLayout();
        return changed;
    }

    void updateScrollLayout() {
        invalidateHierarchy();
        layout();
        if (getParent() instanceof ScrollPane)
            ((ScrollPane) getParent()).layout();
        updateScrollPosition();
    }

    public class ScrollTextAreaListener extends TextAreaListener {
        @Override
        public boolean keyDown(InputEvent event, int keycode) {
            updateScrollPosition();
            return super.keyDown(event, keycode);
        }

        @Override
        public boolean keyTyped(InputEvent event, char character) {
            updateScrollPosition();
            return super.keyTyped(event, character);
        }
    }
}