codepointinputmethod.java

input method tool using java

                buffer.append(c);
                insertionPoint = 9;
                sendComposedText();
            } else {
                beep();
            }
        } else {
            beep();
        }
    }

    /**
     * Send the composed text to the client.
     */
    private void sendComposedText() {
        AttributedString as = new AttributedString(buffer.toString());
        as.addAttribute(TextAttribute.INPUT_METHOD_HIGHLIGHT,
                        InputMethodHighlight.SELECTED_RAW_TEXT_HIGHLIGHT);
        context.dispatchInputMethodEvent(
                                  InputMethodEvent.INPUT_METHOD_TEXT_CHANGED,
                                  as.getIterator(), 0,
                                  TextHitInfo.leading(insertionPoint), null);
    }

    /**
     * Send the committed text to the client.
     */
    private void sendCommittedText() {
        AttributedString as = new AttributedString(buffer.toString());
        context.dispatchInputMethodEvent(
                                  InputMethodEvent.INPUT_METHOD_TEXT_CHANGED,
                                  as.getIterator(), buffer.length(),
                                  TextHitInfo.leading(insertionPoint), null);

        buffer.setLength(0);
        insertionPoint = 0;
        format = UNSET;
    }

    /**
     * Move the insertion point one position to the left in the composed text.
     * Do not let the caret move to the left of the "\\u" or "\\U".
     */
    private void moveCaretLeft() {
        int len = buffer.length();
        if (--insertionPoint < 2) {
            insertionPoint++;
            beep();
        } else if (format == SURROGATE_PAIR && insertionPoint == 7) {
            insertionPoint = 8;
            beep();
        }

        context.dispatchInputMethodEvent(
                                  InputMethodEvent.CARET_POSITION_CHANGED,
                                  null, 0,
                                  TextHitInfo.leading(insertionPoint), null);
    }

    /**
     * Move the insertion point one position to the right in the composed text.
     */
    private void moveCaretRight() {
        int len = buffer.length();
        if (++insertionPoint > len) {
            insertionPoint = len;
            beep();
        }

        context.dispatchInputMethodEvent(
                                  InputMethodEvent.CARET_POSITION_CHANGED,
                                  null, 0,
                                  TextHitInfo.leading(insertionPoint), null);
    }

    /**
     * Delete the character preceding the insertion point in the composed text.
     * If the insertion point is not at the end of the composed text and the
     * preceding text is "\\u" or "\\U", ring the bell.
     */
    private void deletePreviousCharacter() {
        if (insertionPoint == 2) {
            if (buffer.length() == 2) {
                cancelComposition();
            } else {
                // Do not allow deletion of the leading "\\u" or "\\U" if there
                // are other digits in the composed text.
                beep();
            }
        } else if (insertionPoint == 8) {
            if (buffer.length() == 8) {
                if (format == SURROGATE_PAIR) {
                    buffer.deleteCharAt(--insertionPoint);
                }
                buffer.deleteCharAt(--insertionPoint);
                sendComposedText();
            } else {
                // Do not allow deletion of the second "\\u" if there are other
                // digits in the composed text.
                beep();
            }
        } else {
            buffer.deleteCharAt(--insertionPoint);
            if (buffer.length() == 0) {
                sendCommittedText();
            } else {
                sendComposedText();
            }
        }
    }

    /**
     * Delete the character following the insertion point in the composed text.
     * If the insertion point is at the end of the composed text, ring the bell.
     */
    private void deleteCharacter() {
        if (insertionPoint < buffer.length()) {
            buffer.deleteCharAt(insertionPoint);
            sendComposedText();
        } else {
            beep();
        }
    }

    private void startComposition() {
        buffer.append('\\');
        insertionPoint = 1;
        sendComposedText();
    }

    private void cancelComposition() {
        buffer.setLength(0);
        insertionPoint = 0;
        sendCommittedText();
    }

    private void finishComposition() {
        int len = buffer.length();
        if (len == 6 && format != SPECIAL_ESCAPE) {
            char codePoint = (char)getCodePoint(buffer, 2, 5);
            if (Character.isValidCodePoint(codePoint) && codePoint != 0xFFFF) {
                buffer.setLength(0);
                buffer.append(codePoint);
	        sendCommittedText();
                return;
            }
        } else if (len == 8 && format == SPECIAL_ESCAPE) {
            int codePoint = getCodePoint(buffer, 2, 7);
            if (Character.isValidCodePoint(codePoint) && codePoint != 0xFFFF) {
                buffer.setLength(0);
                buffer.appendCodePoint(codePoint);
	        sendCommittedText();
                return;
            }
        } else if (len == 12 && format == SURROGATE_PAIR) {
	    char[] codePoint = {
                (char)getCodePoint(buffer, 2, 5),
	        (char)getCodePoint(buffer, 8, 11)
            };
            if (Character.isHighSurrogate(codePoint[0]) &&
                Character.isLowSurrogate(codePoint[1])) {
	        buffer.setLength(0);
	        buffer.append(codePoint);
	        sendCommittedText();
                return;
            }
        }

        beep();
    }

    private int getCodePoint(StringBuffer sb, int from, int to) {
        int value = 0;
        for (int i = from; i <= to; i++) {
            value = (value<<4) + Character.digit(sb.charAt(i), 16);
        }
        return value;
    }

    private static void beep() {
        Toolkit.getDefaultToolkit().beep();
    }


    public void activate() {
        if (buffer == null) {
            buffer = new StringBuffer(12);
            insertionPoint = 0;
        }
    }

    public void deactivate(boolean isTemporary) {
        if (!isTemporary) {
            buffer = null;
        }
    }

    public void dispose() {
    }

    public Object getControlObject() {
        return null;
    }

    public void endComposition() {
        sendCommittedText();
    }

    public Locale getLocale() {
        return locale;
    }

    public void hideWindows() {
    }

    public boolean isCompositionEnabled() {
        // always enabled
        return true;
    }

    public void notifyClientWindowChange(Rectangle location) {
    }

    public void reconvert() {
        // not supported yet
        throw new UnsupportedOperationException();
    }

    public void removeNotify() {
    }

    public void setCharacterSubsets(Character.Subset[] subsets) {
    }

    public void setCompositionEnabled(boolean enable) {
        // not supported yet
        throw new UnsupportedOperationException();
    }

    public void setInputMethodContext(InputMethodContext context) {
        this.context = context;
    }

    /*
     * The Code Point Input Method supports all locales.
     */
    public boolean setLocale(Locale locale) {
        this.locale = locale;
        return true;
    }
}