alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Java example source code file (CInputMethod.java)

This example Java source code file (CInputMethod.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

attributedstring, awt, can\'t, cinputmethod, cplatformwindow, event, font, hashmap, inputmethodevent, integer, invocationtargetexception, jtextcomponent, locale, lwcomponentpeer, reflection, runnable, string, text, texthitinfo, util

The CInputMethod.java Java example source code

/*
 * Copyright (c) 2011, 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * 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
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * 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).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package sun.lwawt.macosx;

import java.awt.im.spi.*;
import java.util.*;
import java.awt.*;
import java.awt.peer.*;
import java.awt.event.*;
import java.awt.im.*;
import java.awt.font.*;
import java.lang.Character.Subset;
import java.lang.reflect.InvocationTargetException;
import java.text.AttributedCharacterIterator.Attribute;
import java.text.*;
import javax.swing.text.JTextComponent;

import sun.awt.im.InputMethodAdapter;
import sun.lwawt.*;

public class CInputMethod extends InputMethodAdapter {
    private InputMethodContext fIMContext;
    private Component fAwtFocussedComponent;
    private LWComponentPeer fAwtFocussedComponentPeer;
    private boolean isActive;

    private static Map<TextAttribute, Integer>[] sHighlightStyles;

    // Intitalize highlight mapping table and its mapper.
    static {
        Map<TextAttribute, Integer> styles[] = new Map[4];
        HashMap<TextAttribute, Integer> map;

        // UNSELECTED_RAW_TEXT_HIGHLIGHT
        map = new HashMap<TextAttribute, Integer>(1);
        map.put(TextAttribute.INPUT_METHOD_UNDERLINE,
                TextAttribute.UNDERLINE_LOW_GRAY);
        styles[0] = Collections.unmodifiableMap(map);

        // SELECTED_RAW_TEXT_HIGHLIGHT
        map = new HashMap<TextAttribute, Integer>(1);
        map.put(TextAttribute.INPUT_METHOD_UNDERLINE,
                TextAttribute.UNDERLINE_LOW_GRAY);
        styles[1] = Collections.unmodifiableMap(map);

        // UNSELECTED_CONVERTED_TEXT_HIGHLIGHT
        map = new HashMap<TextAttribute, Integer>(1);
        map.put(TextAttribute.INPUT_METHOD_UNDERLINE,
                TextAttribute.UNDERLINE_LOW_ONE_PIXEL);
        styles[2] = Collections.unmodifiableMap(map);

        // SELECTED_CONVERTED_TEXT_HIGHLIGHT
        map = new HashMap<TextAttribute, Integer>(1);
        map.put(TextAttribute.INPUT_METHOD_UNDERLINE,
                TextAttribute.UNDERLINE_LOW_TWO_PIXEL);
        styles[3] = Collections.unmodifiableMap(map);

        sHighlightStyles = styles;

        nativeInit();

    }

    public CInputMethod() {
    }


    /**
        * Sets the input method context, which is used to dispatch input method
     * events to the client component and to request information from
     * the client component.
     * <p>
     * This method is called once immediately after instantiating this input
     * method.
     *
     * @param context the input method context for this input method
     * @exception NullPointerException if <code>context is null
     */
    public void setInputMethodContext(InputMethodContext context) {
        fIMContext = context;
    }

    /**
        * Attempts to set the input locale. If the input method supports the
     * desired locale, it changes its behavior to support input for the locale
     * and returns true.
     * Otherwise, it returns false and does not change its behavior.
     * <p>
     * This method is called
     * <ul>
     * <li>by {@link java.awt.im.InputContext#selectInputMethod InputContext.selectInputMethod},
     * <li>when switching to this input method through the user interface if the user
     *     specified a locale or if the previously selected input method's
     *     {@link java.awt.im.spi.InputMethod#getLocale getLocale} method
     *     returns a non-null value.
     * </ul>
     *
     * @param lang locale to input
     * @return whether the specified locale is supported
     * @exception NullPointerException if <code>locale is null
     */
    public boolean setLocale(Locale lang) {
        return setLocale(lang, false);
    }

    private boolean setLocale(Locale lang, boolean onActivate) {
        Object[] available = CInputMethodDescriptor.getAvailableLocalesInternal();
        for (int i = 0; i < available.length; i++) {
            Locale locale = (Locale)available[i];
            if (lang.equals(locale) ||
                // special compatibility rule for Japanese and Korean
                locale.equals(Locale.JAPAN) && lang.equals(Locale.JAPANESE) ||
                locale.equals(Locale.KOREA) && lang.equals(Locale.KOREAN)) {
                if (isActive) {
                    setNativeLocale(locale.toString(), onActivate);
                }
                return true;
            }
        }
        return false;
    }

    /**
        * Returns the current input locale. Might return null in exceptional cases.
     * <p>
     * This method is called
     * <ul>
     * <li>by {@link java.awt.im.InputContext#getLocale InputContext.getLocale} and
     * <li>when switching from this input method to a different one through the
     *     user interface.
     * </ul>
     *
     * @return the current input locale, or null
     */
    public Locale getLocale() {
        // On Mac OS X we'll ask the currently active input method what its locale is.
        Locale returnValue = getNativeLocale();
        if (returnValue == null) {
            returnValue = Locale.getDefault();
        }

        return returnValue;
    }

    /**
        * Sets the subsets of the Unicode character set that this input method
     * is allowed to input. Null may be passed in to indicate that all
     * characters are allowed.
     * <p>
     * This method is called
     * <ul>
     * <li>immediately after instantiating this input method,
     * <li>when switching to this input method from a different one, and
     * <li>by {@link java.awt.im.InputContext#setCharacterSubsets InputContext.setCharacterSubsets}.
     * </ul>
     *
     * @param subsets the subsets of the Unicode character set from which
     * characters may be input
     */
    public void setCharacterSubsets(Subset[] subsets) {
        // -- SAK: Does mac OS X support this?
    }

    /**
        * Composition cannot be set on Mac OS X -- the input method remembers this
     */
    public void setCompositionEnabled(boolean enable) {
        throw new UnsupportedOperationException("Can't adjust composition mode on Mac OS X.");
    }

    public boolean isCompositionEnabled() {
        throw new UnsupportedOperationException("Can't adjust composition mode on Mac OS X.");
    }

    /**
     * Dispatches the event to the input method. If input method support is
     * enabled for the focussed component, incoming events of certain types
     * are dispatched to the current input method for this component before
     * they are dispatched to the component's methods or event listeners.
     * The input method decides whether it needs to handle the event. If it
     * does, it also calls the event's <code>consume method; this
     * causes the event to not get dispatched to the component's event
     * processing methods or event listeners.
     * <p>
     * Events are dispatched if they are instances of InputEvent or its
     * subclasses.
     * This includes instances of the AWT classes KeyEvent and MouseEvent.
     * <p>
     * This method is called by {@link java.awt.im.InputContext#dispatchEvent InputContext.dispatchEvent}.
     *
     * @param event the event being dispatched to the input method
     * @exception NullPointerException if <code>event is null
     */
    public void dispatchEvent(final AWTEvent event) {
        // No-op for Mac OS X.
    }


    /**
     * Activate and deactivate are no-ops on Mac OS X.
     * A non-US keyboard layout is an 'input method' in that it generates events the same way as
     * a CJK input method. A component that doesn't want input method events still wants the dead-key
     * events.
     *
     *
     */
    public void activate() {
        isActive = true;
    }

    public void deactivate(boolean isTemporary) {
        isActive = false;
    }

    /**
     * Closes or hides all windows opened by this input method instance or
     * its class.  Deactivate hides windows for us on Mac OS X.
     */
    public void hideWindows() {
    }

    long getNativeViewPtr(LWComponentPeer peer) {
        if (peer.getPlatformWindow() instanceof CPlatformWindow) {
            CPlatformWindow platformWindow = (CPlatformWindow) peer.getPlatformWindow();
            CPlatformView platformView = platformWindow.getContentView();
            return platformView.getAWTView();
        } else {
            return 0;
        }
    }

    /**
        * Notifies the input method that a client component has been
     * removed from its containment hierarchy, or that input method
     * support has been disabled for the component.
     */
    public void removeNotify() {
        if (fAwtFocussedComponentPeer != null) {
            nativeEndComposition(getNativeViewPtr(fAwtFocussedComponentPeer));
        }

        fAwtFocussedComponentPeer = null;
    }

    /**
     * Informs the input method adapter about the component that has the AWT
     * focus if it's using the input context owning this adapter instance.
     * We also take the opportunity to tell the native side that we are the input method
     * to talk to when responding to key events.
     */
    protected void setAWTFocussedComponent(Component component) {
        LWComponentPeer peer = null;
        long modelPtr = 0;
        CInputMethod imInstance = this;

        // component will be null when we are told there's no focused component.
        // When that happens we need to notify the native architecture to stop generating IMEs
        if (component == null) {
            peer = fAwtFocussedComponentPeer;
            imInstance = null;
        } else {
            peer = getNearestNativePeer(component);

            // If we have a passive client, don't pass input method events to it.
            if (component.getInputMethodRequests() == null) {
                imInstance = null;
            }
        }

        if (peer != null) {
            modelPtr = getNativeViewPtr(peer);

            // modelPtr refers to the ControlModel that either got or lost focus.
            nativeNotifyPeer(modelPtr, imInstance);
        }

        // Track the focused component and its nearest peer.
        fAwtFocussedComponent = component;
        fAwtFocussedComponentPeer = getNearestNativePeer(component);
    }

    /**
        * @see java.awt.Toolkit#mapInputMethodHighlight
     */
    public static Map mapInputMethodHighlight(InputMethodHighlight highlight) {
        int index;
        int state = highlight.getState();
        if (state == InputMethodHighlight.RAW_TEXT) {
            index = 0;
        } else if (state == InputMethodHighlight.CONVERTED_TEXT) {
            index = 2;
        } else {
            return null;
        }
        if (highlight.isSelected()) {
            index += 1;
        }
        return sHighlightStyles[index];
    }

    /**
        * Ends any input composition that may currently be going on in this
     * context. Depending on the platform and possibly user preferences,
     * this may commit or delete uncommitted text. Any changes to the text
     * are communicated to the active component using an input method event.
     *
     * <p>
     * A text editing component may call this in a variety of situations,
     * for example, when the user moves the insertion point within the text
     * (but outside the composed text), or when the component's text is
     * saved to a file or copied to the clipboard.
     * <p>
     * This method is called
     * <ul>
     * <li>by {@link java.awt.im.InputContext#endComposition InputContext.endComposition},
     * <li>by {@link java.awt.im.InputContext#dispatchEvent InputContext.dispatchEvent}
     *     when switching to a different client component
     * <li>when switching from this input method to a different one using the
     *     user interface or
     *     {@link java.awt.im.InputContext#selectInputMethod InputContext.selectInputMethod}.
     * </ul>
     */
    public void endComposition() {
        if (fAwtFocussedComponentPeer != null)
            nativeEndComposition(getNativeViewPtr(fAwtFocussedComponentPeer));
    }

    /**
        * Disposes of the input method and releases the resources used by it.
     * In particular, the input method should dispose windows and close files that are no
     * longer needed.
     * <p>
     * This method is called by {@link java.awt.im.InputContext#dispose InputContext.dispose}.
     * <p>
     * The method is only called when the input method is inactive.
     * No method of this interface is called on this instance after dispose.
     */
    public void dispose() {
        fIMContext = null;
        fAwtFocussedComponent = null;
        fAwtFocussedComponentPeer = null;
    }

    /**
        * Returns a control object from this input method, or null. A
     * control object provides methods that control the behavior of the
     * input method or obtain information from the input method. The type
     * of the object is an input method specific class. Clients have to
     * compare the result against known input method control object
     * classes and cast to the appropriate class to invoke the methods
     * provided.
     * <p>
     * This method is called by
     * {@link java.awt.im.InputContext#getInputMethodControlObject InputContext.getInputMethodControlObject}.
     *
     * @return a control object from this input method, or null
     */
    public Object getControlObject() {
        return null;
    }

    // java.awt.Toolkit#getNativeContainer() is not available
    //    from this package
    private LWComponentPeer getNearestNativePeer(Component comp) {
        if (comp==null)
            return null;

        ComponentPeer peer = comp.getPeer();
        if (peer==null)
            return null;

        while (peer instanceof java.awt.peer.LightweightPeer) {
            comp = comp.getParent();
            if (comp==null)
                return null;
            peer = comp.getPeer();
            if (peer==null)
                return null;
        }

        if (peer instanceof LWComponentPeer)
            return (LWComponentPeer)peer;

        return null;
    }

    // =========================== NSTextInput callbacks ===========================
    // The 'marked text' that we get from Cocoa.  We need to track this separately, since
    // Java doesn't let us ask the IM context for it.
    private AttributedString fCurrentText = null;
    private String fCurrentTextAsString = null;
    private int fCurrentTextLength = 0;

    /**
     * Tell the component to commit all of the characters in the string to the current
     * text view. This effectively wipes out any text in progress.
     */
    synchronized private void insertText(String aString) {
        AttributedString attribString = new AttributedString(aString);

        // Set locale information on the new string.
        attribString.addAttribute(Attribute.LANGUAGE, getLocale(), 0, aString.length());

        TextHitInfo theCaret = TextHitInfo.afterOffset(aString.length() - 1);
        InputMethodEvent event = new InputMethodEvent(fAwtFocussedComponent,
                                                      InputMethodEvent.INPUT_METHOD_TEXT_CHANGED,
                                                      attribString.getIterator(),
                                                      aString.length(),
                                                      theCaret,
                                                      theCaret);
        LWCToolkit.postEvent(LWCToolkit.targetToAppContext(fAwtFocussedComponent), event);
        fCurrentText = null;
        fCurrentTextAsString = null;
        fCurrentTextLength = 0;
    }

    private void startIMUpdate (String rawText) {
        fCurrentTextAsString = new String(rawText);
        fCurrentText = new AttributedString(fCurrentTextAsString);
        fCurrentTextLength = rawText.length();
    }

    static private final int kCaretPosition = 0;
    static private final int kRawText = 1;
    static private final int kSelectedRawText = 2;
    static private final int kConvertedText = 3;
    static private final int kSelectedConvertedText = 4;

    /**
     * Convert Cocoa text highlight attributes into Java input method highlighting.
     */
    private void addAttribute (boolean isThickUnderline, boolean isGray, int start, int length) {
        int begin = start;
        int end = start + length;
        int markupType = kRawText;

        if (isThickUnderline && isGray) {
            markupType = kRawText;
        } else if (!isThickUnderline && isGray) {
            markupType = kRawText;
        } else if (isThickUnderline && !isGray) {
            markupType = kSelectedConvertedText;
        } else if (!isThickUnderline && !isGray) {
            markupType = kConvertedText;
        }

        InputMethodHighlight theHighlight;

        switch (markupType) {
            case kSelectedRawText:
                theHighlight = InputMethodHighlight.SELECTED_RAW_TEXT_HIGHLIGHT;
                break;
            case kConvertedText:
                theHighlight = InputMethodHighlight.UNSELECTED_CONVERTED_TEXT_HIGHLIGHT;
                break;
            case kSelectedConvertedText:
                theHighlight = InputMethodHighlight.SELECTED_CONVERTED_TEXT_HIGHLIGHT;
                break;
            case kRawText:
            default:
                theHighlight = InputMethodHighlight.UNSELECTED_RAW_TEXT_HIGHLIGHT;
                break;
        }

        fCurrentText.addAttribute(TextAttribute.INPUT_METHOD_HIGHLIGHT, theHighlight, begin, end);
    }

   /* Called from JNI to select the previously typed glyph during press and hold */
    private void selectPreviousGlyph() {
        if (fIMContext == null) return; // ???
        try {
            LWCToolkit.invokeLater(new Runnable() {
                public void run() {
                    final int offset = fIMContext.getInsertPositionOffset();
                    if (offset < 1) return; // ???

                    if (fAwtFocussedComponent instanceof JTextComponent) {
                        ((JTextComponent) fAwtFocussedComponent).select(offset - 1, offset);
                        return;
                    }

                    if (fAwtFocussedComponent instanceof TextComponent) {
                        ((TextComponent) fAwtFocussedComponent).select(offset - 1, offset);
                        return;
                    }
                    // TODO: Ideally we want to disable press-and-hold in this case
                }
            }, fAwtFocussedComponent);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private void selectNextGlyph() {
        if (fIMContext == null || !(fAwtFocussedComponent instanceof JTextComponent)) return;
        try {
            LWCToolkit.invokeLater(new Runnable() {
                public void run() {
                    final int offset = fIMContext.getInsertPositionOffset();
                    if (offset < 0) return;
                    ((JTextComponent) fAwtFocussedComponent).select(offset, offset + 1);
                    return;
                }
            }, fAwtFocussedComponent);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private void dispatchText(int selectStart, int selectLength, boolean pressAndHold) {
        // Nothing to do if we have no text.
        if (fCurrentText == null)
            return;

        TextHitInfo theCaret = (selectLength == 0 ? TextHitInfo.beforeOffset(selectStart) : null);
        TextHitInfo visiblePosition = TextHitInfo.beforeOffset(0);

        InputMethodEvent event = new InputMethodEvent(fAwtFocussedComponent,
                                                      InputMethodEvent.INPUT_METHOD_TEXT_CHANGED,
                                                      fCurrentText.getIterator(),
                                                      0,
                                                      theCaret,
                                                      visiblePosition);
        LWCToolkit.postEvent(LWCToolkit.targetToAppContext(fAwtFocussedComponent), event);

        if (pressAndHold) selectNextGlyph();
    }

    /**
     * Frequent callbacks from NSTextInput.  I think we're supposed to commit it here?
     */
    synchronized private void unmarkText() {
        if (fCurrentText == null)
            return;

        TextHitInfo theCaret = TextHitInfo.afterOffset(fCurrentTextLength);
        TextHitInfo visiblePosition = theCaret;
        InputMethodEvent event = new InputMethodEvent(fAwtFocussedComponent,
                                                      InputMethodEvent.INPUT_METHOD_TEXT_CHANGED,
                                                      fCurrentText.getIterator(),
                                                      fCurrentTextLength,
                                                      theCaret,
                                                      visiblePosition);
        LWCToolkit.postEvent(LWCToolkit.targetToAppContext(fAwtFocussedComponent), event);
        fCurrentText = null;
        fCurrentTextAsString = null;
        fCurrentTextLength = 0;
    }

    synchronized private boolean hasMarkedText() {
        return fCurrentText != null;
    }

    /**
        * Cocoa assumes the marked text and committed text is all stored in the same storage, but
     * Java does not.  So, we have to see where the request is and based on that return the right
     * substring.
     */
    synchronized private String attributedSubstringFromRange(final int locationIn, final int lengthIn) {
        final String[] retString = new String[1];

        try {
            LWCToolkit.invokeAndWait(new Runnable() {
                public void run() { synchronized(retString) {
                    int location = locationIn;
                    int length = lengthIn;

                    if ((location + length) > (fIMContext.getCommittedTextLength() + fCurrentTextLength)) {
                        length = fIMContext.getCommittedTextLength() - location;
                    }

                    AttributedCharacterIterator theIterator = null;

                    if (fCurrentText == null) {
                        theIterator = fIMContext.getCommittedText(location, location + length, null);
                    } else {
                        int insertSpot = fIMContext.getInsertPositionOffset();

                        if (location < insertSpot) {
                            theIterator = fIMContext.getCommittedText(location, location + length, null);
                        } else if (location >= insertSpot && location < insertSpot + fCurrentTextLength) {
                            theIterator = fCurrentText.getIterator(null, location - insertSpot, location - insertSpot +length);
                        } else  {
                            theIterator = fIMContext.getCommittedText(location - fCurrentTextLength, location - fCurrentTextLength + length, null);
                        }
                    }

                    // Get the characters from the iterator
                    char selectedText[] = new char[theIterator.getEndIndex() - theIterator.getBeginIndex()];
                    char current = theIterator.first();
                    int index = 0;
                    while (current != CharacterIterator.DONE) {
                        selectedText[index++] = current;
                        current = theIterator.next();
                    }

                    retString[0] = new String(selectedText);
                }}
            }, fAwtFocussedComponent);
        } catch (InvocationTargetException ite) { ite.printStackTrace(); }

        synchronized(retString) { return retString[0]; }
    }

    /**
     * Cocoa wants the range of characters that are currently selected.  We have to synthesize this
     * by getting the insert location and the length of the selected text. NB:  This does NOT allow
     * for the fact that the insert point in Swing can come AFTER the selected text, making this
     * potentially incorrect.
     */
    synchronized private int[] selectedRange() {
        final int[] returnValue = new int[2];

        try {
            LWCToolkit.invokeAndWait(new Runnable() {
                public void run() { synchronized(returnValue) {
                    AttributedCharacterIterator theIterator = fIMContext.getSelectedText(null);
                    if (theIterator == null) {
                        returnValue[0] = fIMContext.getInsertPositionOffset();
                        returnValue[1] = 0;
                        return;
                    }

                    int startLocation;

                    if (fAwtFocussedComponent instanceof JTextComponent) {
                        JTextComponent theComponent = (JTextComponent)fAwtFocussedComponent;
                        startLocation = theComponent.getSelectionStart();
                    } else if (fAwtFocussedComponent instanceof TextComponent) {
                        TextComponent theComponent = (TextComponent)fAwtFocussedComponent;
                        startLocation = theComponent.getSelectionStart();
                    } else {
                        // If we don't have a Swing or AWT component, we have to guess whether the selection is before or after the input spot.
                        startLocation = fIMContext.getInsertPositionOffset() - (theIterator.getEndIndex() - theIterator.getBeginIndex());

                        // If the calculated spot is negative the insert spot must be at the beginning of
                        // the selection.
                        if (startLocation <  0) {
                            startLocation = fIMContext.getInsertPositionOffset() + (theIterator.getEndIndex() - theIterator.getBeginIndex());
                        }
                    }

                    returnValue[0] = startLocation;
                    returnValue[1] = theIterator.getEndIndex() - theIterator.getBeginIndex();

                }}
            }, fAwtFocussedComponent);
        } catch (InvocationTargetException ite) { ite.printStackTrace(); }

        synchronized(returnValue) { return returnValue; }
    }

    /**
     * Cocoa wants the range of characters that are currently marked.  Since Java doesn't store committed and
     * text in progress (composed text) together, we have to synthesize it.  We know where the text will be
     * inserted, so we can return that position, and the length of the text in progress.  If there is no marked text
     * return null.
     */
    synchronized private int[] markedRange() {
        if (fCurrentText == null)
            return null;

        final int[] returnValue = new int[2];

        try {
            LWCToolkit.invokeAndWait(new Runnable() {
                public void run() { synchronized(returnValue) {
                    // The insert position is always after the composed text, so the range start is the
                    // insert spot less the length of the composed text.
                    returnValue[0] = fIMContext.getInsertPositionOffset();
                }}
            }, fAwtFocussedComponent);
        } catch (InvocationTargetException ite) { ite.printStackTrace(); }

        returnValue[1] = fCurrentTextLength;
        synchronized(returnValue) { return returnValue; }
    }

    /**
     * Cocoa wants a rectangle that describes where a particular range is on screen, but only cares about the
     * location of that rectangle.  We are given the index of the character for which we want the location on
     * screen, which will be a character in the in-progress text.  By subtracting the current insert position,
     * which is always in front of the in-progress text, we get the offset into the composed text, and we get
     * that location from the input method context.
     */
    synchronized private int[] firstRectForCharacterRange(final int absoluteTextOffset) {
        final int[] rect = new int[4];

        try {
            LWCToolkit.invokeAndWait(new Runnable() {
                public void run() { synchronized(rect) {
                    int insertOffset = fIMContext.getInsertPositionOffset();
                    int composedTextOffset = absoluteTextOffset - insertOffset;
                    if (composedTextOffset < 0) composedTextOffset = 0;
                    Rectangle r = fIMContext.getTextLocation(TextHitInfo.beforeOffset(composedTextOffset));
                    rect[0] = r.x;
                    rect[1] = r.y;
                    rect[2] = r.width;
                    rect[3] = r.height;

                    // This next if-block is a hack to work around a bug in JTextComponent. getTextLocation ignores
                    // the TextHitInfo passed to it and always returns the location of the insertion point, which is
                    // at the start of the composed text.  We'll do some calculation so the candidate window for Kotoeri
                    // follows the requested offset into the composed text.
                    if (composedTextOffset > 0 && (fAwtFocussedComponent instanceof JTextComponent)) {
                        Rectangle r2 = fIMContext.getTextLocation(TextHitInfo.beforeOffset(0));

                        if (r.equals(r2)) {
                            // FIXME: (SAK) If the candidate text wraps over two lines, this calculation pushes the candidate
                            // window off the right edge of the component.
                            String inProgressSubstring = fCurrentTextAsString.substring(0, composedTextOffset);
                            Graphics g = fAwtFocussedComponent.getGraphics();
                            int xOffset = g.getFontMetrics().stringWidth(inProgressSubstring);
                            rect[0] += xOffset;
                            g.dispose();
                        }
                    }
                }}
            }, fAwtFocussedComponent);
        } catch (InvocationTargetException ite) { ite.printStackTrace(); }

        synchronized(rect) { return rect; }
    }

    /* This method returns the index for the character that is nearest to the point described by screenX and screenY.
     * The coordinates are in Java screen coordinates.  If no character in the composed text was hit, we return -1, indicating
     * not found.
     */
    synchronized private int characterIndexForPoint(final int screenX, final int screenY) {
        final TextHitInfo[] offsetInfo = new TextHitInfo[1];
        final int[] insertPositionOffset = new int[1];

        try {
            LWCToolkit.invokeAndWait(new Runnable() {
                public void run() { synchronized(offsetInfo) {
                    offsetInfo[0] = fIMContext.getLocationOffset(screenX, screenY);
                    insertPositionOffset[0] = fIMContext.getInsertPositionOffset();
                }}
            }, fAwtFocussedComponent);
        } catch (InvocationTargetException ite) { ite.printStackTrace(); }

        // This bit of gymnastics ensures that the returned location is within the composed text.
        // If it falls outside that region, the input method will commit the text, which is inconsistent with native
        // Cocoa apps (see TextEdit, for example.)  Clicking to the left of or above the selected text moves the
        // cursor to the start of the composed text, and to the right or below moves it to one character before the end.
        if (offsetInfo[0] == null) {
            return insertPositionOffset[0];
        }

        int returnValue = offsetInfo[0].getCharIndex() + insertPositionOffset[0];

        if (offsetInfo[0].getCharIndex() == fCurrentTextLength)
            returnValue --;

        return returnValue;
    }

    // On Mac OS X we effectively disabled the input method when focus was lost, so
    // this call can be ignored.
    public void disableInputMethod()
    {
        // Deliberately ignored. See setAWTFocussedComponent above.
    }

    public String getNativeInputMethodInfo()
    {
        return nativeGetCurrentInputMethodInfo();
    }


    // =========================== Native methods ===========================
    // Note that if nativePeer isn't something that normally accepts keystrokes (i.e., a CPanel)
    // these calls will be ignored.
    private native void nativeNotifyPeer(long nativePeer, CInputMethod imInstance);
    private native void nativeEndComposition(long nativePeer);
    private native void nativeHandleEvent(LWComponentPeer peer, AWTEvent event);

    // Returns the locale of the active input method.
    static native Locale getNativeLocale();

    // Switches to the input method with language indicated in localeName
    static native boolean setNativeLocale(String localeName, boolean onActivate);

    // Returns information about the currently selected input method.
    static native String nativeGetCurrentInputMethodInfo();

    // Initialize toolbox routines
    static native void nativeInit();
}

Other Java examples (source code examples)

Here is a short list of links related to this Java CInputMethod.java source code file:

... this post is sponsored by my books ...

#1 New Release!

FP Best Seller

 

new blog posts

 

Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.