LWTextComponentPeer.java

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
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 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
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 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
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package sun.lwawt;

import java.awt.Dimension;
import java.awt.FontMetrics;
import java.awt.Insets;
import java.awt.SystemColor;
import java.awt.TextComponent;
import java.awt.event.TextEvent;
import java.awt.event.InputMethodListener;
import java.awt.event.InputMethodEvent;
import java.awt.im.InputMethodRequests;
import java.awt.peer.TextComponentPeer;
import sun.awt.AWTAccessor;

import javax.swing.JComponent;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
import javax.swing.text.Document;
import javax.swing.text.JTextComponent;

/**
 * Lightweight implementation of {@link TextComponentPeer}. Provides useful
 * methods for {@link LWTextAreaPeer} and {@link LWTextFieldPeer}
 */
abstract class LWTextComponentPeer<T extends TextComponent, D extends JComponent>
        extends LWComponentPeer<T, D>
        implements DocumentListener, TextComponentPeer, InputMethodListener {

    private volatile boolean firstChangeSkipped;

    LWTextComponentPeer(final T target,
                        final PlatformComponent platformComponent) {
        super(target, platformComponent);
        if (!getTarget().isBackgroundSet()) {
            getTarget().setBackground(SystemColor.text);
        }
    }

    @Override
    void initializeImpl() {
        super.initializeImpl();
        synchronized (getDelegateLock()) {
            // This listener should be added before setText().
            getTextComponent().getDocument().addDocumentListener(this);
        }
        setEditable(getTarget().isEditable());
        setText(getTarget().getText());
        setCaretPosition(getTarget().getCaretPosition());
        getTarget().addInputMethodListener(this);
        final int start = getTarget().getSelectionStart();
        final int end = getTarget().getSelectionEnd();
        if (end > start) {
            // Should be called after setText() and setCaretPosition()
            select(start, end);
        }
        firstChangeSkipped = true;
    }

    @Override
    protected final void disposeImpl() {
        synchronized (getDelegateLock()) {
            // visible caret has a timer thread which must be stopped
            getTextComponent().getCaret().setVisible(false);
        }
        super.disposeImpl();
    }

    /**
     * This method should be called under getDelegateLock().
     */
    abstract JTextComponent getTextComponent();

    public Dimension getMinimumSize(final int rows, final int columns) {
        final Insets insets;
        synchronized (getDelegateLock()) {
            insets = getTextComponent().getInsets();
        }
        final int borderHeight = insets.top + insets.bottom;
        final int borderWidth = insets.left + insets.right;
        final FontMetrics fm = getFontMetrics(getFont());
        return new Dimension(fm.charWidth(WIDE_CHAR) * columns + borderWidth,
                             fm.getHeight() * rows + borderHeight);
    }

    @Override
    public final void setEditable(final boolean editable) {
        synchronized (getDelegateLock()) {
            getTextComponent().setEditable(editable);
        }
    }

    @Override
    public final String getText() {
        synchronized (getDelegateLock()) {
            return getTextComponent().getText();
        }
    }

    @Override
    public final void setText(final String text) {
        synchronized (getDelegateLock()) {
            // JTextArea.setText() posts two different events (remove & insert).
            // Since we make no differences between text events,
            // the document listener has to be disabled while
            // JTextArea.setText() is called.
            final Document document = getTextComponent().getDocument();
            document.removeDocumentListener(this);
            getTextComponent().setText(text);
            revalidate();
            if (firstChangeSkipped) {
                postEvent(new TextEvent(getTarget(),
                                        TextEvent.TEXT_VALUE_CHANGED));
            }
            document.addDocumentListener(this);
        }
        repaintPeer();
    }

    @Override
    public final int getSelectionStart() {
        synchronized (getDelegateLock()) {
            return getTextComponent().getSelectionStart();
        }
    }

    @Override
    public final int getSelectionEnd() {
        synchronized (getDelegateLock()) {
            return getTextComponent().getSelectionEnd();
        }
    }

    @Override
    public final void select(final int selStart, final int selEnd) {
        synchronized (getDelegateLock()) {
            getTextComponent().select(selStart, selEnd);
        }
        repaintPeer();
    }

    @Override
    public final void setCaretPosition(final int pos) {
        synchronized (getDelegateLock()) {
            getTextComponent().setCaretPosition(pos);
        }
        repaintPeer();
    }

    @Override
    public final int getCaretPosition() {
        synchronized (getDelegateLock()) {
            return getTextComponent().getCaretPosition();
        }
    }

    @Override
    public final InputMethodRequests getInputMethodRequests() {
        synchronized (getDelegateLock()) {
            return getTextComponent().getInputMethodRequests();
        }
    }

    //TODO IN XAWT we just return true..
    @Override
    public final boolean isFocusable() {
        return getTarget().isFocusable();
    }

    protected final void revalidate() {
        synchronized (getDelegateLock()) {
            getTextComponent().invalidate();
            getDelegate().validate();
        }
    }

    protected final void postTextEvent() {
        postEvent(new TextEvent(getTarget(), TextEvent.TEXT_VALUE_CHANGED));
        synchronized (getDelegateLock()) {
            revalidate();
        }
    }

    @Override
    public final void changedUpdate(final DocumentEvent e) {
        postTextEvent();
    }

    @Override
    public final void insertUpdate(final DocumentEvent e) {
        postTextEvent();
    }

    @Override
    public final void removeUpdate(final DocumentEvent e) {
        postTextEvent();
    }

    @Override
    public void inputMethodTextChanged(final InputMethodEvent event) {
        synchronized (getDelegateLock()) {
            AWTAccessor.getComponentAccessor().processEvent(getTextComponent(), event);
        }
    }

    @Override
    public void caretPositionChanged(final InputMethodEvent event) {
        synchronized (getDelegateLock()) {
            AWTAccessor.getComponentAccessor().processEvent(getTextComponent(), event);
        }
    }
}