javafx.scene.control.IndexRange#getLength ( )源码实例Demo

@Override
protected void setSecondAreaSelection() {
    if (isSettingValues || displayArea == null || !contentSplitPane.getItems().contains(displayArea)) {
        return;
    }
    displayArea.deselect();
    IndexRange hexRange = mainArea.getSelection();
    if (hexRange.getLength() == 0) {
        return;
    }
    isSettingValues = true;
    final String text = displayArea.getText();
    if (!text.isEmpty()) {
        IndexRange textRange = ByteTools.textIndex(mainArea.getText(), sourceInformation.getCharset(), hexRange);
        displayArea.selectRange(textRange.getStart(), textRange.getEnd());
        displayArea.setScrollTop(mainArea.getScrollTop());
    }
    isSettingValues = false;
}
 

/**
 * Transfers the currently selected text to the clipboard,
 * leaving the current selection.
 */
default void copy() {
    IndexRange selection = getSelection();
    if(selection.getLength() > 0) {
        ClipboardContent content = new ClipboardContent();

        content.putString(getSelectedText());

        getStyleCodecs().ifPresent(codecs -> {
            Codec<StyledDocument<PS, SEG, S>> codec = ReadOnlyStyledDocument.codec(codecs._1, codecs._2, getSegOps());
            DataFormat format = dataFormat(codec.getName());
            StyledDocument<PS, SEG, S> doc = subDocument(selection.getStart(), selection.getEnd());
            ByteArrayOutputStream os = new ByteArrayOutputStream();
            DataOutputStream dos = new DataOutputStream(os);
            try {
                codec.encode(dos, doc);
                content.put(format, os.toByteArray());
            } catch (IOException e) {
                System.err.println("Codec error: Exception in encoding '" + codec.getName() + "':");
                e.printStackTrace();
            }
        });

        Clipboard.getSystemClipboard().setContent(content);
    }
}
 

/**
 * If something is currently selected and the given position is outside of the selection, moves the selected
 * rich-text document to the given position by deleting it from the area and re-inserting it at the given position.
 * If nothing is selected, moves the caret ot that position.
 */
default void moveSelectedText(int position) {
    IndexRange sel = getSelection();

    if((position >= sel.getStart() && position <= sel.getEnd()) || sel.equals(GenericStyledArea.EMPTY_RANGE)) {
        // no move, just position the caret
        selectRange(position, position);
    } else {
        StyledDocument<PS, SEG, S> text = this.subDocument(sel.getStart(), sel.getEnd());
        if(position > sel.getEnd())
            position -= sel.getLength();

        createMultiChange(2)
                .deleteText(sel)
                .insertAbsolutely(position, text)
                .commit();

        // select moved text
        selectRange(position, position + text.length());
    }
}
 

private void handleFirstPrimaryPress(MouseEvent e) {
    // ensure focus
    view.requestFocus();

    CharacterHit hit = view.hit(e.getX(), e.getY());

    view.clearTargetCaretOffset();
    IndexRange selection = view.getSelection();
    if(view.isEditable() &&
            selection.getLength() != 0 &&
            hit.getCharacterIndex().isPresent() &&
            hit.getCharacterIndex().getAsInt() >= selection.getStart() &&
            hit.getCharacterIndex().getAsInt() < selection.getEnd()) {
        // press inside selection
        dragSelection = DragState.POTENTIAL_DRAG;
        dragNewSelection = DragState.NO_DRAG;
    } else {
        dragSelection = DragState.NO_DRAG;
        dragNewSelection = DragState.NO_DRAG;
        view.getOnOutsideSelectionMousePressed().handle(e);
    }
}
 

protected void addTextAround(String prefix, String suffix) {
    IndexRange range = mainArea.getSelection();
    if (range.getLength() == 0) {
        String s = prefix + message("Text") + suffix;
        mainArea.insertText(range.getStart(), s);
        mainArea.selectRange(range.getStart() + prefix.length(),
                range.getStart() + prefix.length() + message("Text").length());
    } else {
        mainArea.insertText(range.getStart(), prefix);
        mainArea.insertText(range.getEnd() + prefix.length(), suffix);
    }
    mainArea.requestFocus();
}
 

public static int mapInt(int value, IndexRange originalRange, IndexRange newlRange) {
    if (originalRange == null || newlRange == null || originalRange.getStart() > value || originalRange.getEnd() < value) {
        return value;
    }
    int len = value - originalRange.getStart() + 1;
    double ratio = newlRange.getLength() * 1.0 / originalRange.getLength();
    return newlRange.getStart() + (int) Math.round(len * ratio);
}
 

private void backspacePressed(KeyEvent e) {
	IndexRange selection = textArea.getSelection();
	int start = selection.getStart();
	int end = selection.getEnd();
	if (selection.getLength() > 0) {
		// selection is not empty --> delete selected text
		deleteText(textArea, start, end);
	} else {
		// selection is empty
		int startLine = offsetToLine(start);
		int startLineOffset = lineToStartOffset(startLine);
		if (start > startLineOffset && textArea.getText(startLineOffset, start).trim().isEmpty()) {
			// selection is empty and caret is in leading whitespace of a line,
			// but not at the beginning of a line --> unindent line
			indentSelectedLines(false);
		} else {
			String line = textArea.getText(startLine);
			int startLineEndOffset = startLineOffset + line.length();
			Matcher matcher = (start == startLineEndOffset) ? AUTO_INDENT_PATTERN.matcher(line) : null;
			if (matcher != null && matcher.matches() && matcher.group(2).isEmpty()) {
				// caret is at end of line and line contains only whitespace characters
				// and auto-indentable markers --> empty line
				deleteText(textArea, startLineOffset, startLineEndOffset);
			} else if (start > 0) {
				// delete character before caret
				deleteText(textArea, start - 1, start);
			}
		}
	}
}
 

/**
 * Returns whether an indent operation should used for the selection.
 *
 * Returns true if:
 *  - selection spans multiple lines
 *  - selection is empty and caret is in leading whitespace of a line
 *  - a single line is completely selected (excluding line separator)
 */
private boolean isIndentSelection() {
	IndexRange selection = textArea.getSelection();
	int start = selection.getStart();
	int startLine = offsetToLine(start);
	if (selection.getLength() == 0)
		return textArea.getText(lineToStartOffset(startLine), start).trim().isEmpty();
	else {
		int end = selection.getEnd();
		int endLine = offsetToLine(end);
		return endLine > startLine ||
			   lineToStartOffset(startLine) == start && lineToEndOffset(startLine) == end;
	}
}
 

private void updateStyleInSelection(Function<StyleSpans<TextStyle>, TextStyle> mixinGetter) {
    IndexRange selection = area.getSelection();
    if(selection.getLength() != 0) {
        StyleSpans<TextStyle> styles = area.getStyleSpans(selection);
        TextStyle mixin = mixinGetter.apply(styles);
        StyleSpans<TextStyle> newStyles = styles.mapStyles(style -> style.updateWith(mixin));
        area.setStyleSpans(selection.getStart(), newStyles);
    }
}
 

private void updateStyleInSelection(TextStyle mixin) {
    IndexRange selection = area.getSelection();
    if (selection.getLength() != 0) {
        StyleSpans<TextStyle> styles = area.getStyleSpans(selection);
        StyleSpans<TextStyle> newStyles = styles.mapStyles(style -> style.updateWith(mixin));
        area.setStyleSpans(selection.getStart(), newStyles);
    }
}
 

private void deleteBackward(KeyEvent ignore) {
    IndexRange selection = view.getSelection();
    if(selection.getLength() == 0) {
        view.deletePreviousChar();
    } else {
        view.replaceSelection("");
    }
}
 

private void deleteForward(KeyEvent ignore) {
    IndexRange selection = view.getSelection();
    if(selection.getLength() == 0) {
        view.deleteNextChar();
    } else {
        view.replaceSelection("");
    }
}
 

private void left(KeyEvent ignore) {
    IndexRange sel = view.getSelection();
    if(sel.getLength() == 0) {
        view.previousChar(SelectionPolicy.CLEAR);
    } else {
        view.moveTo(sel.getStart(), SelectionPolicy.CLEAR);
    }
}
 

private void right(KeyEvent ignore) {
    IndexRange sel = view.getSelection();
    if(sel.getLength() == 0) {
        view.nextChar(SelectionPolicy.CLEAR);
    } else {
        view.moveTo(sel.getEnd(), SelectionPolicy.CLEAR);
    }
}