Have icon for "reset" entry in reflog

[egit/eclipse.git] / org.eclipse.egit.ui / src / org / eclipse / egit / ui / internal / commit / LogicalLineNumberRulerColumn.java

/*******************************************************************************
 * Copyright (C) 2016, Thomas Wolf <thomas.wolf@paranor.ch>
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *******************************************************************************/
package org.eclipse.egit.ui.internal.commit;

import org.eclipse.core.runtime.Assert;
import org.eclipse.jface.text.ITextViewer;
import org.eclipse.jface.text.source.LineNumberRulerColumn;
import org.eclipse.jgit.annotations.NonNull;
import org.eclipse.jgit.diff.DiffEntry;

/**
 * A {@link LineNumberRulerColumn} that uses an
 * {@link ILogicalLineNumberProvider} to determine the line numbers to show.
 */
public class LogicalLineNumberRulerColumn extends LineNumberRulerColumn {

        private ILogicalLineNumberProvider logicalLineNumberProvider;

        private final @NonNull DiffEntry.Side side;

        /**
         * Zoom level for workaround for HiDPI line number rulers on macOS retina.
         *
         * @see <a href="https://bugs.eclipse.org/516322">Bug 516322</a>
         */
        int zoom = 100;

        /**
         * @param side
         */
        public LogicalLineNumberRulerColumn(@NonNull DiffEntry.Side side) {
                this.side = side;
        }

        /**
         * @return the {@link DiffEntry} side
         */
        protected @NonNull DiffEntry.Side getSide() {
                return side;
        }

        /**
         * Retrieves the {@link ILogicalLineNumberProvider} to use. This
         * implementation returns a {@link LogicalLineNumberProvider}.
         *
         * @return the {@link ILogicalLineNumberProvider}
         */
        protected ILogicalLineNumberProvider getLogicalLineNumberProvider() {
                if (logicalLineNumberProvider == null) {
                        ITextViewer viewer = getParentRuler().getTextViewer();
                        Assert.isNotNull(viewer);
                        logicalLineNumberProvider = new LogicalLineNumberProvider(getSide(),
                                        viewer);
                }
                return logicalLineNumberProvider;
        }

        @Override
        protected String createDisplayString(int line) {
                int logicalLine = getLogicalLineNumberProvider().getLogicalLine(line);
                return logicalLine < 0 ? "" : Integer.toString(logicalLine + 1); //$NON-NLS-1$
        }

        @Override
        protected int computeNumberOfDigits() {
                int max = getLogicalLineNumberProvider().getMaximum();
                int digits = 2;
                while (max > Math.pow(10, digits) - 1) {
                        ++digits;
                }
                return digits;
        }

        /**
         * Enable workaround for HiDPI line number rulers on macOS retina. This
         * method will override an internal method in Oxygen (4.7).
         *
         * @return true
         * @see <a href="https://bugs.eclipse.org/516322">Bug 516322</a>
         */
        protected boolean internalSupportsZoomedPaint() {
                return true;
        }

        /**
         * Store zoom level for workaround for HiDPI line number rulers on macOS
         * retina. This method will override an internal method in Oxygen (4.7).
         *
         * @param zoomLevel
         *            the zoom level to use for drawing operations
         * @see <a href="https://bugs.eclipse.org/516322">Bug 516322</a>
         */
        protected void internalSetZoom(int zoomLevel) {
                this.zoom = zoomLevel;
        }
}