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/*******************************************************************************
 * Copyright (c) 2006, 2016 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Tom Eicher (Avaloq Evolution AG) - block selection mode
 *******************************************************************************/
package org.eclipse.jface.text;

import org.eclipse.swt.custom.StyledText;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;

import org.eclipse.jface.internal.text.SelectionProcessor;

import org.eclipse.jface.text.source.ILineRange;
import org.eclipse.jface.text.source.LineRange;

/**
 * A collection of JFace Text functions.
 * 

* This class is neither intended to be instantiated nor subclassed. *

* * @since 3.3 * @noinstantiate This class is not intended to be instantiated by clients. */ public final class JFaceTextUtil { private JFaceTextUtil() { // Do not instantiate } /** * Computes the full line height for the text line corresponding to the given widget line, * considering the possible line wrapping. * * @param styledText the widget * @param widgetLine the widget line * @return the full real height of the corresponding line of text (which might wrap to multiple * widget lines) in the widget * @since 3.11 */ public static int computeLineHeight(StyledText styledText, int widgetLine) { boolean isWrapActive= styledText.getWordWrap(); int lineHeight; int offset= styledText.getOffsetAtLine(widgetLine); if (!isWrapActive) { lineHeight= styledText.getLineHeight(offset); } else { int offsetEnd= offset + styledText.getLine(widgetLine).length(); if (offsetEnd == styledText.getCharCount()) { lineHeight= styledText.getLineHeight(offset); } else { Rectangle textBounds= styledText.getTextBounds(offset, offsetEnd); lineHeight= textBounds.height; } } return lineHeight; } /** * Computes the line height for the given line range. * * @param textWidget the StyledText widget * @param startLine the start line * @param endLine the end line (exclusive) * @param lineCount the line count used by the old API * @return the height of all lines starting with startLine and ending above endLime */ public static int computeLineHeight(StyledText textWidget, int startLine, int endLine, int lineCount) { return getLinePixel(textWidget, endLine) - getLinePixel(textWidget, startLine); } /** * Returns the last fully visible line of the widget. The exact semantics of "last fully visible * line" are: *
    *
  • the last line of which the last pixel is visible, if any *
  • otherwise, the only line that is partially visible *
* * @param widget the widget * @return the last fully visible line */ public static int getBottomIndex(StyledText widget) { int lastPixel= computeLastVisiblePixel(widget); // bottom is in [0 .. lineCount - 1] int bottom= widget.getLineIndex(lastPixel); // bottom is the first line - no more checking if (bottom == 0) return bottom; int pixel= widget.getLinePixel(bottom); // bottom starts on or before the client area start - bottom is the only visible line if (pixel <= 0) return bottom; int height= computeLineHeight(widget, bottom); // bottom is not showing entirely - use the previous line if (pixel + height - 1 > lastPixel) return bottom - 1; // bottom is fully visible and its last line is exactly the last pixel return bottom; } /** * Returns the index of the first (possibly only partially) visible line of the widget * * @param widget the widget * @return the index of the first line of which a pixel is visible */ public static int getPartialTopIndex(StyledText widget) { // see StyledText#getPartialTopIndex() int top= widget.getTopIndex(); int pixels= widget.getLinePixel(top); if (pixels > 0) top--; return top; } /** * Returns the index of the last (possibly only partially) visible line of the widget * * @param widget the text widget * @return the index of the last line of which a pixel is visible */ public static int getPartialBottomIndex(StyledText widget) { // @see StyledText#getPartialBottomIndex() int lastPixel= computeLastVisiblePixel(widget); int bottom= widget.getLineIndex(lastPixel); return bottom; } /** * Returns the last visible pixel in the widget's client area. * * @param widget the widget * @return the last visible pixel in the widget's client area */ private static int computeLastVisiblePixel(StyledText widget) { int caHeight= widget.getClientArea().height; int lastPixel= caHeight - 1; // XXX: what if there is a margin? can't take trim as this includes the scrollbars which are not part of the client area // if ((textWidget.getStyle() & SWT.BORDER) != 0) // lastPixel -= 4; return lastPixel; } /** * Returns the line index of the first visible model line in the viewer. The line may be only * partially visible. * * @param viewer the text viewer * @return the first line of which a pixel is visible, or -1 for no line */ public static int getPartialTopIndex(ITextViewer viewer) { StyledText widget= viewer.getTextWidget(); int widgetTop= getPartialTopIndex(widget); return widgetLine2ModelLine(viewer, widgetTop); } /** * Returns the last, possibly partially, visible line in the view port. * * @param viewer the text viewer * @return the last, possibly partially, visible line in the view port */ public static int getPartialBottomIndex(ITextViewer viewer) { StyledText textWidget= viewer.getTextWidget(); int widgetBottom= getPartialBottomIndex(textWidget); return widgetLine2ModelLine(viewer, widgetBottom); } /** * Returns the range of lines that is visible in the viewer, including any partially visible * lines. * * @param viewer the viewer * @return the range of lines that is visible in the viewer, null if no lines are * visible */ public static ILineRange getVisibleModelLines(ITextViewer viewer) { int top= getPartialTopIndex(viewer); int bottom= getPartialBottomIndex(viewer); if (top == -1 || bottom == -1) return null; return new LineRange(top, bottom - top + 1); } /** * Converts a widget line into a model (i.e. {@link IDocument}) line using the * {@link ITextViewerExtension5} if available, otherwise by adapting the widget line to the * viewer's {@link ITextViewer#getVisibleRegion() visible region}. * * @param viewer the viewer * @param widgetLine the widget line to convert. * @return the model line corresponding to widgetLine or -1 to signal that there * is no corresponding model line */ public static int widgetLine2ModelLine(ITextViewer viewer, int widgetLine) { int modelLine; if (viewer instanceof ITextViewerExtension5) { ITextViewerExtension5 extension= (ITextViewerExtension5) viewer; modelLine= extension.widgetLine2ModelLine(widgetLine); } else { try { IRegion r= viewer.getVisibleRegion(); IDocument d= viewer.getDocument(); if (d == null) return -1; modelLine= widgetLine + d.getLineOfOffset(r.getOffset()); } catch (BadLocationException x) { modelLine= widgetLine; } } return modelLine; } /** * Converts a model (i.e. {@link IDocument}) line into a widget line using the * {@link ITextViewerExtension5} if available, otherwise by adapting the model line to the * viewer's {@link ITextViewer#getVisibleRegion() visible region}. * * @param viewer the viewer * @param modelLine the model line to convert. * @return the widget line corresponding to modelLine or -1 to signal that there * is no corresponding widget line */ public static int modelLineToWidgetLine(ITextViewer viewer, final int modelLine) { int widgetLine; if (viewer instanceof ITextViewerExtension5) { ITextViewerExtension5 extension= (ITextViewerExtension5) viewer; widgetLine= extension.modelLine2WidgetLine(modelLine); } else { IRegion region= viewer.getVisibleRegion(); IDocument document= viewer.getDocument(); if (document == null) return -1; try { int visibleStartLine= document.getLineOfOffset(region.getOffset()); int visibleEndLine= document.getLineOfOffset(region.getOffset() + region.getLength()); if (modelLine < visibleStartLine || modelLine > visibleEndLine) widgetLine= -1; else widgetLine= modelLine - visibleStartLine; } catch (BadLocationException x) { // ignore and return -1 widgetLine= -1; } } return widgetLine; } /** * Returns the number of hidden pixels of the first partially visible line. If there is no * partially visible line, zero is returned. * * @param textWidget the widget * @return the number of hidden pixels of the first partial line, always >= 0 */ public static int getHiddenTopLinePixels(StyledText textWidget) { int top= getPartialTopIndex(textWidget); return -textWidget.getLinePixel(top); } /* * @see StyledText#getLinePixel(int) */ public static int getLinePixel(StyledText textWidget, int line) { return textWidget.getLinePixel(line); } /* * @see StyledText#getLineIndex(int) */ public static int getLineIndex(StyledText textWidget, int y) { int lineIndex= textWidget.getLineIndex(y); return lineIndex; } /** * Returns true if the widget displays the entire contents, i.e. it cannot * be vertically scrolled. * * @param widget the widget * @return true if the widget displays the entire contents, i.e. it cannot * be vertically scrolled, false otherwise */ public static boolean isShowingEntireContents(StyledText widget) { if (widget.getTopPixel() != 0) // more efficient shortcut return false; int lastVisiblePixel= computeLastVisiblePixel(widget); int lastPossiblePixel= widget.getLinePixel(widget.getLineCount()); return lastPossiblePixel <= lastVisiblePixel; } /** * Determines the graphical area covered by the given text region in * the given viewer. * * @param region the region whose graphical extend must be computed * @param textViewer the text viewer containing the region * @return the graphical extend of the given region in the given viewer * * @since 3.4 */ public static Rectangle computeArea(IRegion region, ITextViewer textViewer) { int start= 0; int end= 0; IRegion widgetRegion= modelRange2WidgetRange(region, textViewer); if (widgetRegion != null) { start= widgetRegion.getOffset(); end= start + widgetRegion.getLength(); } StyledText styledText= textViewer.getTextWidget(); Rectangle bounds; if (end > 0 && start < end) bounds= styledText.getTextBounds(start, end - 1); else { Point loc= styledText.getLocationAtOffset(start); bounds= new Rectangle(loc.x, loc.y, getAverageCharWidth(textViewer.getTextWidget()), computeLineHeight(styledText, styledText.getLineAtOffset(start))); } return new Rectangle(bounds.x, bounds.y, bounds.width, bounds.height); } /** * Translates a given region of the text viewer's document into * the corresponding region of the viewer's widget. * * @param region the document region * @param textViewer the viewer containing the region * @return the corresponding widget region * * @since 3.4 */ private static IRegion modelRange2WidgetRange(IRegion region, ITextViewer textViewer) { if (textViewer instanceof ITextViewerExtension5) { ITextViewerExtension5 extension= (ITextViewerExtension5) textViewer; return extension.modelRange2WidgetRange(region); } IRegion visibleRegion= textViewer.getVisibleRegion(); int start= region.getOffset() - visibleRegion.getOffset(); int end= start + region.getLength(); if (end > visibleRegion.getLength()) end= visibleRegion.getLength(); return new Region(start, end - start); } /** * Returns the average character width of the given control's font. * * @param control the control to calculate the average char width for * @return the average character width of the controls font * * @since 3.4 */ public static int getAverageCharWidth(Control control) { GC gc= new GC(control); gc.setFont(control.getFont()); int increment= gc.getFontMetrics().getAverageCharWidth(); gc.dispose(); return increment; } /** * Returns true if the text covered by selection does not contain any * characters in the given viewer. Note the difference to {@link ITextSelection#isEmpty()}, * which returns true only for invalid selections. * * @param viewer the viewer * @param selection the selection * @return true if selection does not contain any text, * false otherwise * @throws BadLocationException if accessing the document failed * @since 3.5 */ public static boolean isEmpty(ITextViewer viewer, ITextSelection selection) throws BadLocationException { return new SelectionProcessor(viewer).isEmpty(selection); } /** * Returns the text regions covered by the given selection in the given viewer. * * @param viewer the viewer * @param selection the selection * @return the text regions corresponding to selection * @throws BadLocationException if accessing the document failed * @since 3.5 */ public static IRegion[] getCoveredRanges(ITextViewer viewer, ITextSelection selection) throws BadLocationException { return new SelectionProcessor(viewer).getRanges(selection); } /** * Returns the offset in the given viewer that corresponds to the current cursor location. * * @param viewer the viewer * @return the offset for the current cursor location or -1 if not available * @since 3.5 */ public static int getOffsetForCursorLocation(ITextViewer viewer) { try { StyledText text= viewer.getTextWidget(); if (text == null || text.isDisposed()) return -1; Display display= text.getDisplay(); Point absolutePosition= display.getCursorLocation(); Point relativePosition= text.toControl(absolutePosition); int widgetOffset= text.getOffsetAtLocation(relativePosition); Point p= text.getLocationAtOffset(widgetOffset); if (p.x > relativePosition.x) widgetOffset--; if (viewer instanceof ITextViewerExtension5) { ITextViewerExtension5 extension= (ITextViewerExtension5)viewer; return extension.widgetOffset2ModelOffset(widgetOffset); } return widgetOffset + viewer.getVisibleRegion().getOffset(); } catch (IllegalArgumentException e) { return -1; } } }




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