Bug 576377 - Provide shortcuts/commands for incrementalI20220314-1800I20220313-1800I20220312-1800I20220312-0100I20220311-1800

multiselection/multiple carets in text editors

Add various commands for multi-selection (intended for keyboard usage,
keyboard shortcuts are just suggestions):
- AddAllMatchesToMultiSelection (e.g. CTRL-ALT-SHIFT-J)
- AddNextMatchToMultiSelection (e.g. ALT-J)
- RemoveLastMatchFromMultiSelectionHandler (e.g. ALT-SHIFT-J)
- StopMultiSelectionHandler (e.g. ESC)

Change-Id: Id9add4daad15495ee00c76d8a5a7c5dc5608f506
Reviewed-on: https://git.eclipse.org/r/c/platform/eclipse.platform.text/+/191500
Tested-by: Platform Bot <platform-bot@eclipse.org>
Reviewed-by: Mickael Istria <mistria@redhat.com>

12 files changed, 897 insertions, 9 deletions

diff --git a/org.eclipse.ui.editors.tests/META-INF/MANIFEST.MF b/org.eclipse.ui.editors.tests/META-INF/MANIFEST.MF
index 47dd5a5b647..5ece30fa9b8 100644
--- a/org.eclipse.ui.editors.tests/META-INF/MANIFEST.MF
+++ b/org.eclipse.ui.editors.tests/META-INF/MANIFEST.MF
@@ -2,7 +2,7 @@ Manifest-Version: 1.0
 Bundle-ManifestVersion: 2
 Bundle-Name: %Plugin.name
 Bundle-SymbolicName: org.eclipse.ui.editors.tests;singleton:=true
-Bundle-Version: 3.12.400.qualifier
+Bundle-Version: 3.12.500.qualifier
 Bundle-Vendor: %Plugin.providerName
 Bundle-Localization: plugin
 Export-Package: org.eclipse.ui.editors.tests
@@ -11,7 +11,7 @@ Require-Bundle:
  org.junit;bundle-version="4.12.0",
  org.eclipse.jface;bundle-version="[3.5.0,4.0.0)",
  org.eclipse.text;bundle-version="[3.5.0,4.0.0)",
- org.eclipse.ui.workbench.texteditor;bundle-version="[3.5.0,4.0.0)",
+ org.eclipse.ui.workbench.texteditor;bundle-version="[3.16.500,4.0.0)",
  org.eclipse.ui.editors;bundle-version="[3.5.0,4.0.0)",
  org.eclipse.ui.workbench;bundle-version="[3.5.0,4.0.0)",
  org.eclipse.core.resources;bundle-version="[3.14.0,4.0.0)",
diff --git a/org.eclipse.ui.editors.tests/pom.xml b/org.eclipse.ui.editors.tests/pom.xml
index 81baf23f58e..26ee84a16a6 100644
--- a/org.eclipse.ui.editors.tests/pom.xml
+++ b/org.eclipse.ui.editors.tests/pom.xml
@@ -18,7 +18,7 @@
     <relativePath>../tests-pom/</relativePath>
   </parent>
   <artifactId>org.eclipse.ui.editors.tests</artifactId>
-  <version>3.12.400-SNAPSHOT</version>
+  <version>3.12.500-SNAPSHOT</version>
   <packaging>eclipse-test-plugin</packaging>
   <properties>
   	<testSuite>${project.artifactId}</testSuite>
diff --git a/org.eclipse.ui.editors.tests/src/org/eclipse/ui/editors/tests/EditorsTestSuite.java b/org.eclipse.ui.editors.tests/src/org/eclipse/ui/editors/tests/EditorsTestSuite.java
index 74c52d215c7..4dea7310cc7 100644
--- a/org.eclipse.ui.editors.tests/src/org/eclipse/ui/editors/tests/EditorsTestSuite.java
+++ b/org.eclipse.ui.editors.tests/src/org/eclipse/ui/editors/tests/EditorsTestSuite.java
@@ -1,5 +1,5 @@
-/*******************************************************************************
- * Copyright (c) 2000, 2019 IBM Corporation and others.
+/************************************************************************************************
+ * Copyright (c) 2000, 2022 IBM Corporation and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
@@ -11,7 +11,8 @@
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *     Mickael Istria (Red Hat Inc.) - [484157] Add zoom test
- *******************************************************************************/
+ *     Dirk Steinkamp <dirk.steinkamp@gmx.de> - [576377] Add multi caret selection commands test
+ ************************************************************************************************/
 package org.eclipse.ui.editors.tests;
 
 import org.junit.runner.RunWith;
@@ -36,7 +37,9 @@ import org.junit.runners.Suite.SuiteClasses;
 		TextFileDocumentProviderTest.class,
 		StatusEditorTest.class,
 		TextNavigationTest.class,
-		LargeFileTest.class, CaseActionTest.class
+		LargeFileTest.class, CaseActionTest.class,
+		TextMultiCaretNavigationTest.class,
+		TextMultiCaretSelectionCommandsTest.class,
 })
 public class EditorsTestSuite {
 	// see @SuiteClasses
diff --git a/org.eclipse.ui.editors.tests/src/org/eclipse/ui/editors/tests/TextMultiCaretSelectionCommandsTest.java b/org.eclipse.ui.editors.tests/src/org/eclipse/ui/editors/tests/TextMultiCaretSelectionCommandsTest.java
new file mode 100644
index 00000000000..4ddeb9f2db5
--- /dev/null
+++ b/org.eclipse.ui.editors.tests/src/org/eclipse/ui/editors/tests/TextMultiCaretSelectionCommandsTest.java
@@ -0,0 +1,360 @@
+/*******************************************************************************
+ * Copyright (c) 2022 Dirk Steinkamp
+ *
+ * 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
+ *
+ * Contributors:
+ *     Dirk Steinkamp <dirk.steinkamp@gmx.de> - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.ui.editors.tests;
+
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertEquals;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.util.Collections;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import org.eclipse.swt.custom.StyledText;
+import org.eclipse.swt.widgets.Control;
+
+import org.eclipse.core.commands.Command;
+import org.eclipse.core.commands.ExecutionEvent;
+import org.eclipse.core.filesystem.EFS;
+
+import org.eclipse.core.runtime.CoreException;
+
+import org.eclipse.jface.text.IDocument;
+import org.eclipse.jface.text.IMultiTextSelection;
+import org.eclipse.jface.text.IRegion;
+import org.eclipse.jface.text.MultiTextSelection;
+import org.eclipse.jface.text.Region;
+
+import org.eclipse.ui.PartInitException;
+import org.eclipse.ui.PlatformUI;
+import org.eclipse.ui.commands.ICommandService;
+import org.eclipse.ui.ide.IDE;
+
+import org.eclipse.ui.texteditor.AbstractTextEditor;
+
+/*
+ * Note: this test would better fit in the org.eclipse.ui.workbench.texteditor bundle, but initializing
+ * an editor from this bundle is quite tricky without the IDE and EFS utils.
+ */
+public class TextMultiCaretSelectionCommandsTest {
+	private static final String ADD_NEXT_MATCH_TO_MULTI_SELECTION = "org.eclipse.ui.edit.text.select.addNextMatchToMultiSelection";
+	private static final String ADD_ALL_MATCHES_TO_MULTI_SELECTION = "org.eclipse.ui.edit.text.select.addAllMatchesToMultiSelection";
+	private static final String REMOVE_LAST_MATCH_FROM_MULTI_SELECTION = "org.eclipse.ui.edit.text.select.removeLastMatchFromMultiSelection";
+	private static final String STOP_MULTI_SELECTION = "org.eclipse.ui.edit.text.select.stopMultiSelection";
+
+	private static final String LINE_1 = "private static String a;\n";
+	private static final String LINE_2 = "private static String b;\n";
+	private static final String LINE_3 = "private static String c;\n";
+	private static final String LINE_4 = "private static String d";
+
+	private static final int L1_LEN = LINE_1.length();
+	private static final int L2_LEN = LINE_2.length();
+	private static final int L3_LEN = LINE_3.length();
+	private static final int L4_LEN = LINE_4.length();
+
+	private static File file;
+	private static AbstractTextEditor editor;
+	private static StyledText widget;
+
+	@Before
+	public void setUpBeforeClass() throws IOException, PartInitException, CoreException {
+		file = File.createTempFile(TextMultiCaretSelectionCommandsTest.class.getName(), ".txt");
+		Files.write(file.toPath(), (LINE_1 + LINE_2 + LINE_3 + LINE_4) //
+				.getBytes());
+		editor = (AbstractTextEditor) IDE.openEditorOnFileStore(
+				PlatformUI.getWorkbench().getActiveWorkbenchWindow().getActivePage(), EFS.getStore(file.toURI()));
+		widget = (StyledText) editor.getAdapter(Control.class);
+	}
+
+	@After
+	public void tearDown() {
+		editor.dispose();
+		file.delete();
+	}
+
+	@Test
+	public void testAddNextMatch_withFirstIdentifierSelected_addsIdenticalIdentifiersToSelection() throws Exception {
+		setSelection(new IRegion[] { new Region(0, 7) });
+		assertEquals(7, widget.getCaretOffset());
+
+		executeCommand(ADD_NEXT_MATCH_TO_MULTI_SELECTION);
+
+		assertEquals(7, widget.getCaretOffset());
+		assertArrayEquals(new IRegion[] { new Region(0, 7), new Region(L1_LEN, 7) }, getSelection());
+
+		executeCommand(ADD_NEXT_MATCH_TO_MULTI_SELECTION);
+
+		assertEquals(7, widget.getCaretOffset());
+		assertArrayEquals(new IRegion[] { new Region(0, 7), new Region(L1_LEN, 7), new Region(L1_LEN + L2_LEN, 7) },
+				getSelection());
+
+		executeCommand(STOP_MULTI_SELECTION);
+		assertEquals(7, widget.getCaretOffset());
+		assertArrayEquals(new IRegion[] { new Region(7, 0) }, getSelection());
+	}
+
+	@Test
+	public void testAddNextMatch_withSecondIdentifierSelectedIdentifier_addsNextOccurenceToSelection()
+			throws Exception {
+		setSelection(new IRegion[] { new Region(8, 6) });
+		assertEquals(14, widget.getCaretOffset());
+
+		executeCommand(ADD_NEXT_MATCH_TO_MULTI_SELECTION);
+
+		assertEquals(14, widget.getCaretOffset());
+		assertArrayEquals(new IRegion[] { new Region(8, 6), new Region(L1_LEN + 8, 6) }, getSelection());
+	}
+
+	@Test
+	public void testAddNextMatch_withSelectionInSecondRow_addsIdenticalIdentifierInThirdRowToSelection()
+			throws Exception {
+		setSelection(new IRegion[] { new Region(L1_LEN + 8, 6) });
+		assertEquals(L1_LEN + 14, widget.getCaretOffset());
+
+		executeCommand(ADD_NEXT_MATCH_TO_MULTI_SELECTION);
+
+		assertEquals(L1_LEN + 14, widget.getCaretOffset());
+		assertArrayEquals(new IRegion[] { new Region(L1_LEN + 8, 6), new Region(L1_LEN + L2_LEN + 8, 6) },
+				getSelection());
+	}
+
+	@Test
+	public void testAddNextMatch_withCaretInFirstIdentifier_selectsFullIdentifier() throws Exception {
+		setSelection(new IRegion[] { new Region(1, 0) });
+		assertEquals(1, widget.getCaretOffset());
+
+		executeCommand(ADD_NEXT_MATCH_TO_MULTI_SELECTION);
+
+		assertEquals(7, widget.getCaretOffset());
+		assertArrayEquals(new IRegion[] { new Region(0, 7) }, getSelection());
+	}
+
+	@Test
+	public void testAddNextMatch_withCaretInSecondIdentifier_selectsFullIdentifier() throws Exception {
+		setSelection(new IRegion[] { new Region(11, 0) });
+		assertEquals(11, widget.getCaretOffset());
+
+		executeCommand(ADD_NEXT_MATCH_TO_MULTI_SELECTION);
+
+		assertEquals(14, widget.getCaretOffset());
+		assertArrayEquals(new IRegion[] { new Region(8, 6) }, getSelection());
+	}
+
+	@Test
+	public void testAddNextMatch_withCaretBetweenIdentifierCharAndNonIdentifierChar_selectsFullIdentifier()
+			throws Exception {
+		setSelection(new IRegion[] { new Region(23, 0) });
+		assertEquals(23, widget.getCaretOffset());
+
+		executeCommand(ADD_NEXT_MATCH_TO_MULTI_SELECTION);
+
+		assertEquals(23, widget.getCaretOffset());
+		assertArrayEquals(new IRegion[] { new Region(22, 1) }, getSelection());
+	}
+
+	@Test
+	public void testAddNextMatch_withCaretInSecondRow_selectsFullIdentifier() throws Exception {
+		setSelection(new IRegion[] { new Region(L1_LEN + 11, 0) });
+		assertEquals(L1_LEN + 11, widget.getCaretOffset());
+
+		executeCommand(ADD_NEXT_MATCH_TO_MULTI_SELECTION);
+
+		assertEquals(L1_LEN + 14, widget.getCaretOffset());
+		assertArrayEquals(new IRegion[] { new Region(L1_LEN + 8, 6) }, getSelection());
+	}
+
+	@Test
+	public void testAddNextMatch_withCaretInIdentifierWithNoFollowingMatch_selectsFullIdentifier() throws Exception {
+		setSelection(new IRegion[] { new Region(L1_LEN + L2_LEN + L3_LEN + 11, 0) });
+		assertEquals(L1_LEN + L2_LEN + L3_LEN + 11, widget.getCaretOffset());
+
+		executeCommand(ADD_NEXT_MATCH_TO_MULTI_SELECTION);
+
+		assertEquals(L1_LEN + L2_LEN + L3_LEN + 14, widget.getCaretOffset());
+		assertArrayEquals(new IRegion[] { new Region(L1_LEN + L2_LEN + L3_LEN + 8, 6) }, getSelection());
+	}
+
+	@Test
+	public void testAddNextMatch_withCaretAtEndOfDocument_selectsFullIdentifier() throws Exception {
+		setSelection(new IRegion[] { new Region(L1_LEN + L2_LEN + L3_LEN + L4_LEN, 0) });
+		assertEquals(L1_LEN + L2_LEN + L3_LEN + L4_LEN, widget.getCaretOffset());
+
+		executeCommand(ADD_NEXT_MATCH_TO_MULTI_SELECTION);
+
+		assertEquals(L1_LEN + L2_LEN + L3_LEN + L4_LEN, widget.getCaretOffset());
+		assertArrayEquals(new IRegion[] { new Region(L1_LEN + L2_LEN + L3_LEN + L4_LEN - 1, 1) }, getSelection());
+	}
+
+	@Test
+	public void testAddAllMatches_withSingleSelection_selectsAllOccurences() throws Exception {
+		setSelection(new IRegion[] { new Region(0, 7) });
+		assertEquals(7, widget.getCaretOffset());
+
+		executeCommand(ADD_ALL_MATCHES_TO_MULTI_SELECTION);
+
+		assertEquals(7, widget.getCaretOffset());
+		assertArrayEquals(new IRegion[] { new Region(0, 7), new Region(L1_LEN, 7), new Region(L1_LEN + L2_LEN, 7),
+				new Region(L1_LEN + L2_LEN + L3_LEN, 7) }, getSelection());
+	}
+
+	@Test
+	public void testAddAllMatches_withDoubleSelectionOfSameText_selectsAllOccurences() throws Exception {
+		setSelection(new IRegion[] { new Region(0, 7), new Region(L1_LEN, 7) });
+		assertEquals(7, widget.getCaretOffset());
+
+		executeCommand(ADD_ALL_MATCHES_TO_MULTI_SELECTION);
+
+		assertEquals(7, widget.getCaretOffset());
+		assertArrayEquals(new IRegion[] { new Region(0, 7), new Region(L1_LEN, 7), new Region(L1_LEN + L2_LEN, 7),
+				new Region(L1_LEN + L2_LEN + L3_LEN, 7) }, getSelection());
+	}
+
+	@Test
+	public void testAddAllMatches_withDoubleSelectionOfDifferentTexts_doesNotChangeSelection() throws Exception {
+		setSelection(new IRegion[] { new Region(0, 7), new Region(8, 7) });
+		assertEquals(7, widget.getCaretOffset());
+
+		executeCommand(ADD_ALL_MATCHES_TO_MULTI_SELECTION);
+
+		assertEquals(7, widget.getCaretOffset());
+		assertArrayEquals(new IRegion[] { new Region(0, 7), new Region(8, 7) }, getSelection());
+	}
+
+	@Test
+	public void testAddAllMatches_withCaretInIdentifier_selectsAllOccurencesOfIdentifier() throws Exception {
+		setSelection(new IRegion[] { new Region(2, 0) });
+		assertEquals(2, widget.getCaretOffset());
+
+		executeCommand(ADD_ALL_MATCHES_TO_MULTI_SELECTION);
+
+		assertEquals(7, widget.getCaretOffset());
+		assertArrayEquals(new IRegion[] { new Region(0, 7), new Region(L1_LEN, 7), new Region(L1_LEN + L2_LEN, 7),
+				new Region(L1_LEN + L2_LEN + L3_LEN, 7) }, getSelection());
+	}
+
+	@Test
+	public void testRemoveLastMatchFromMultiSelection_withCaretInIdentifier_doesNothing() throws Exception {
+		setSelection(new IRegion[] { new Region(L1_LEN + 11, 0) });
+		assertEquals(L1_LEN + 11, widget.getCaretOffset());
+
+		executeCommand(REMOVE_LAST_MATCH_FROM_MULTI_SELECTION);
+
+		assertEquals(L1_LEN + 11, widget.getCaretOffset());
+		assertArrayEquals(new IRegion[] { new Region(L1_LEN + 11, 0) }, getSelection());
+	}
+
+	@Test
+	public void testRemoveLastMatchFromMultiSelection_withSingleSelection_doesNothing() throws Exception {
+		setSelection(new IRegion[] { new Region(8, 6) });
+		assertEquals(14, widget.getCaretOffset());
+
+		executeCommand(REMOVE_LAST_MATCH_FROM_MULTI_SELECTION);
+
+		assertEquals(14, widget.getCaretOffset());
+		assertArrayEquals(new IRegion[] { new Region(8, 6) }, getSelection());
+	}
+
+	@Test
+	public void testRemoveLastMatchFromMultiSelection_withTwoSelections_removesSecondSelection() throws Exception {
+		setSelection(new IRegion[] { new Region(8, 6), new Region(L1_LEN + 8, 6) });
+		assertEquals(14, widget.getCaretOffset());
+
+		executeCommand(REMOVE_LAST_MATCH_FROM_MULTI_SELECTION);
+
+		assertEquals(14, widget.getCaretOffset());
+		assertArrayEquals(new IRegion[] { new Region(8, 6) }, getSelection());
+	}
+
+	@Test
+	public void testRemoveLastMatchFromMultiSelection_withThreeSelections_removesThirdSelection() throws Exception {
+		setSelection(new IRegion[] { new Region(8, 6), new Region(L1_LEN + 8, 6), new Region(L1_LEN + L2_LEN + 8, 6) });
+		assertEquals(14, widget.getCaretOffset());
+
+		executeCommand(REMOVE_LAST_MATCH_FROM_MULTI_SELECTION);
+
+		assertEquals(14, widget.getCaretOffset());
+		assertArrayEquals(new IRegion[] { new Region(8, 6), new Region(L1_LEN + 8, 6) }, getSelection());
+	}
+
+	@Test
+	public void testStopMultiSelection_withSingleSelection_doesNotChangeSelectionOrCaretOffset() throws Exception {
+		setSelection(new IRegion[] { new Region(0, 7) });
+
+		assertEquals(7, widget.getCaretOffset());
+
+		executeCommand(STOP_MULTI_SELECTION);
+		assertEquals(7, widget.getCaretOffset());
+		assertArrayEquals(new IRegion[] { new Region(0, 7) }, getSelection());
+	}
+
+	@Test
+	public void testStopMultiSelection_withMultiSelection_revokesSelectionAndKeepsFirstCaretOffset() throws Exception {
+		setSelection(new IRegion[] { new Region(0, 7), new Region(L1_LEN, 7) });
+
+		assertEquals(7, widget.getCaretOffset());
+
+		executeCommand(STOP_MULTI_SELECTION);
+		assertEquals(7, widget.getCaretOffset());
+		assertArrayEquals(new IRegion[] { new Region(7, 0) }, getSelection());
+	}
+
+	@Test
+	public void testStopMultiSelection_withMultiSelectionAndCaretAtBeginning_revokesSelectionAndKeepsFirstCaretOffset()
+			throws Exception {
+		setSelection(new IRegion[] { new Region(0, 0), new Region(0, 7), new Region(L1_LEN, 7) });
+		assertEquals(0, widget.getCaretOffset());
+
+		executeCommand(STOP_MULTI_SELECTION);
+		assertEquals(0, widget.getCaretOffset());
+		assertArrayEquals(new IRegion[] { new Region(0, 0) }, getSelection());
+	}
+
+	@Test
+	public void testStopMultiSelection_withMultiSelectionAndCaretAfterLastSelection_revokesSelectionAndKeepsCaretOffset()
+			throws Exception {
+		setSelection(new IRegion[] { new Region(0, 7), new Region(L1_LEN, 7), new Region(L1_LEN + L2_LEN, 7) });
+		assertEquals(7, widget.getCaretOffset());
+
+		executeCommand(ADD_NEXT_MATCH_TO_MULTI_SELECTION);
+		executeCommand(ADD_NEXT_MATCH_TO_MULTI_SELECTION);
+
+		// TODO How to place the caret at the end without dismissing the
+		// selection? Should rather be 57
+		assertEquals(7, widget.getCaretOffset());
+
+		executeCommand(STOP_MULTI_SELECTION);
+		assertEquals(7, widget.getCaretOffset());
+		assertArrayEquals(new IRegion[] { new Region(7, 0) }, getSelection());
+	}
+
+	// Helper methods
+
+	private void executeCommand(String commandId) throws Exception {
+		Command command = PlatformUI.getWorkbench().getService(ICommandService.class).getCommand(commandId);
+		command.executeWithChecks(new ExecutionEvent(command, Collections.EMPTY_MAP, null, null));
+	}
+
+	private void setSelection(IRegion[] regions) {
+		IDocument document = editor.getDocumentProvider().getDocument(editor.getEditorInput());
+		editor.getSelectionProvider().setSelection(new MultiTextSelection(document, regions));
+	}
+
+	private IRegion[] getSelection() {
+		return ((IMultiTextSelection) editor.getSelectionProvider().getSelection()).getRegions();
+	}
+}
diff --git a/org.eclipse.ui.workbench.texteditor/META-INF/MANIFEST.MF b/org.eclipse.ui.workbench.texteditor/META-INF/MANIFEST.MF
index 64ccad74f0f..de37f77a8d1 100644
--- a/org.eclipse.ui.workbench.texteditor/META-INF/MANIFEST.MF
+++ b/org.eclipse.ui.workbench.texteditor/META-INF/MANIFEST.MF
@@ -2,7 +2,7 @@ Manifest-Version: 1.0
 Bundle-ManifestVersion: 2
 Bundle-Name: %pluginName
 Bundle-SymbolicName: org.eclipse.ui.workbench.texteditor; singleton:=true
-Bundle-Version: 3.16.400.qualifier
+Bundle-Version: 3.16.500.qualifier
 Bundle-Activator: org.eclipse.ui.internal.texteditor.TextEditorPlugin
 Bundle-ActivationPolicy: lazy
 Bundle-Vendor: %providerName
diff --git a/org.eclipse.ui.workbench.texteditor/plugin.properties b/org.eclipse.ui.workbench.texteditor/plugin.properties
index f2b4831e9a5..f7bf56102e9 100644
--- a/org.eclipse.ui.workbench.texteditor/plugin.properties
+++ b/org.eclipse.ui.workbench.texteditor/plugin.properties
@@ -1,5 +1,5 @@
 ###############################################################################
-# Copyright (c) 2000, 2015 IBM Corporation and others.
+# Copyright (c) 2000, 2022 IBM Corporation and others.
 #
 # This program and the accompanying materials
 # are made available under the terms of the Eclipse Public License 2.0
@@ -14,6 +14,7 @@
 #     Daesung Ha <nberserk@gmail.com> - update recenter command description
 #     Mickael Istria (Red Hat Inc.) - 469918 Zoom In/Out
 #     Angelo Zerr <angelo.zerr@gmail.com> - [CodeMining] Provide extension point for CodeMining - Bug 528419
+#     Dirk Steinkamp <dirk.steinkamp@gmx.de> - [576377] Add multi caret selection commands
 ###############################################################################
 pluginName= Text Editor Framework
 providerName= Eclipse.org
@@ -158,6 +159,14 @@ command.selectWindowEnd.description = Select to the end of the window
 command.selectWindowEnd.name = Select Window End
 command.selectWindowStart.description = Select to the start of the window
 command.selectWindowStart.name = Select Window Start
+command.selectAddAllMatchesToMultiSelection.description = Looks for all regions matching the current selection or identifier and adds them to a multi-selection 
+command.selectAddAllMatchesToMultiSelection.name = Add all matches to multi-selection
+command.selectAddNextMatchToMultiSelection.description = Looks for the next region matching the current selection and adds it to a multi-selection 
+command.selectAddNextMatchToMultiSelection.name = Add next match to multi-selection
+command.selectRemoveLastMatchFromMultiSelection.description = Reduces the current matching regions of a multi-selection by one 
+command.selectRemoveLastMatchFromMultiSelection.name = Remove last match from multi-selection
+command.stopMultiSelection.description = Unselects all multi-selections returning to a single cursor 
+command.stopMultiSelection.name = End multi-selection
 command.selectWordNext.description = Select the next word
 command.selectWordNext.name = Select Next Word
 command.selectWordPrevious.description = Select the previous word
diff --git a/org.eclipse.ui.workbench.texteditor/plugin.xml b/org.eclipse.ui.workbench.texteditor/plugin.xml
index 18c9f928a8b..f8d54ff2e24 100644
--- a/org.eclipse.ui.workbench.texteditor/plugin.xml
+++ b/org.eclipse.ui.workbench.texteditor/plugin.xml
@@ -305,6 +305,30 @@
 	        id="org.eclipse.ui.edit.text.select.windowEnd">
 	  </command>
 	  <command
+	        name="%command.selectAddAllMatchesToMultiSelection.name"
+	        description="%command.selectAddAllMatchesToMultiSelection.description"
+	        categoryId="org.eclipse.ui.category.textEditor"
+	        id="org.eclipse.ui.edit.text.select.addAllMatchesToMultiSelection">
+	  </command>
+	  <command
+	        name="%command.selectAddNextMatchToMultiSelection.name"
+	        description="%command.selectAddNextMatchToMultiSelection.description"
+	        categoryId="org.eclipse.ui.category.textEditor"
+	        id="org.eclipse.ui.edit.text.select.addNextMatchToMultiSelection">
+	  </command>
+	  <command
+	        name="%command.selectRemoveLastMatchFromMultiSelection.name"
+	        description="%command.selectAddNextMatchToMultiSelection.description"
+	        categoryId="org.eclipse.ui.category.textEditor"
+	        id="org.eclipse.ui.edit.text.select.removeLastMatchFromMultiSelection">
+	  </command>
+	  <command
+	        name="%command.stopMultiSelection.name"
+	        description="%command.stopMultiSelection.description"
+	        categoryId="org.eclipse.ui.category.textEditor"
+	        id="org.eclipse.ui.edit.text.select.stopMultiSelection">
+	  </command>
+	  <command
 	        name="%command.deletePrevious.name"
 	        description="%command.deletePrevious.description"
 	        categoryId="org.eclipse.ui.category.textEditor"
@@ -1365,6 +1389,54 @@
            </with>
          </enabledWhen>
       </handler>
+      <handler
+            class="org.eclipse.ui.internal.texteditor.multiselection.AddAllMatchesToMultiSelectionHandler"
+            commandId="org.eclipse.ui.edit.text.select.addAllMatchesToMultiSelection">
+         <enabledWhen>
+            <with
+                 variable="activeEditor">
+              <instanceof
+                    value="org.eclipse.ui.texteditor.ITextEditor">
+              </instanceof>
+           </with>
+         </enabledWhen>
+      </handler>	
+      <handler
+            class="org.eclipse.ui.internal.texteditor.multiselection.AddNextMatchToMultiSelectionHandler"
+            commandId="org.eclipse.ui.edit.text.select.addNextMatchToMultiSelection">
+         <enabledWhen>
+            <with
+                 variable="activeEditor">
+              <instanceof
+                    value="org.eclipse.ui.texteditor.ITextEditor">
+              </instanceof>
+           </with>
+         </enabledWhen>
+      </handler>
+      <handler
+            class="org.eclipse.ui.internal.texteditor.multiselection.RemoveLastMatchFromMultiSelectionHandler"
+            commandId="org.eclipse.ui.edit.text.select.removeLastMatchFromMultiSelection">
+         <enabledWhen>
+            <with
+                 variable="activeEditor">
+              <instanceof
+                    value="org.eclipse.ui.texteditor.ITextEditor">
+              </instanceof>
+           </with>
+         </enabledWhen>
+      </handler>
+      <handler
+            class="org.eclipse.ui.internal.texteditor.multiselection.StopMultiSelectionHandler"
+            commandId="org.eclipse.ui.edit.text.select.stopMultiSelection">
+         <enabledWhen>
+            <with
+                 variable="activeEditor">
+              <instanceof
+                    value="org.eclipse.ui.texteditor.ITextEditor">
+              </instanceof>
+           </with>
+         </enabledWhen>
+      </handler>
    </extension>
    <extension
          point="org.eclipse.ui.menus">
diff --git a/org.eclipse.ui.workbench.texteditor/src/org/eclipse/ui/internal/texteditor/multiselection/AbstractMultiSelectionHandler.java b/org.eclipse.ui.workbench.texteditor/src/org/eclipse/ui/internal/texteditor/multiselection/AbstractMultiSelectionHandler.java
new file mode 100644
index 00000000000..f54d153cf7b
--- /dev/null
+++ b/org.eclipse.ui.workbench.texteditor/src/org/eclipse/ui/internal/texteditor/multiselection/AbstractMultiSelectionHandler.java
@@ -0,0 +1,294 @@
+/*******************************************************************************
+ * Copyright (c) 2022 Dirk Steinkamp
+ *
+ * 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
+ *
+ * Contributors:
+ *     Dirk Steinkamp <dirk.steinkamp@gmx.de> - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.ui.internal.texteditor.multiselection;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+import org.eclipse.swt.custom.StyledText;
+import org.eclipse.swt.widgets.Control;
+
+import org.eclipse.core.commands.AbstractHandler;
+import org.eclipse.core.commands.ExecutionEvent;
+import org.eclipse.core.commands.ExecutionException;
+
+import org.eclipse.jface.viewers.ISelection;
+
+import org.eclipse.jface.text.BadLocationException;
+import org.eclipse.jface.text.IDocument;
+import org.eclipse.jface.text.IMultiTextSelection;
+import org.eclipse.jface.text.IRegion;
+import org.eclipse.jface.text.MultiTextSelection;
+import org.eclipse.jface.text.Region;
+
+import org.eclipse.ui.IEditorPart;
+import org.eclipse.ui.handlers.HandlerUtil;
+
+import org.eclipse.ui.texteditor.ITextEditor;
+import org.eclipse.ui.texteditor.ITextEditorExtension5;
+
+/**
+ * Common super class for Multi-Selection-actions, containing various helper
+ * methods. Subclasses need to overwrite {@link #execute()}, which is only
+ * invoked if the {@link #textEditor} and {@link #document} could be properly
+ * initialized.
+ *
+ * @see AddAllMatchesToMultiSelectionHandler
+ * @see AddNextMatchToMultiSelectionHandler
+ * @see RemoveLastMatchFromMultiSelectionHandler
+ * @see StopMultiSelectionHandler
+ */
+abstract class AbstractMultiSelectionHandler extends AbstractHandler {
+	private ExecutionEvent event;
+	private ITextEditor textEditor;
+	private IDocument document;
+
+	/**
+	 * This method needs to be overwritten from subclasses to handle the event.
+	 *
+	 * @throws ExecutionException
+	 */
+	public abstract void execute() throws ExecutionException;
+
+	@Override
+	public Object execute(ExecutionEvent event) throws ExecutionException {
+		if (initFrom(event)) {
+			execute();
+		}
+		return null;
+	}
+
+	public ExecutionEvent getEvent() {
+		return event;
+	}
+
+	protected boolean isMultiSelectionActive() {
+		IRegion[] regions = getSelectedRegions();
+		return regions != null && regions.length > 1;
+	}
+
+	protected boolean nothingSelected() {
+		IRegion[] regions = getSelectedRegions();
+		return regions == null || regions.length == 0 || regions[0].getLength() == 0;
+	}
+
+	protected IRegion[] getSelectedRegions() {
+		ISelection selection = textEditor.getSelectionProvider().getSelection();
+
+		if (!(selection instanceof IMultiTextSelection)) {
+			return null;
+		}
+
+		return ((IMultiTextSelection) selection).getRegions();
+	}
+
+	protected IRegion offsetAsCaretRegion(int offset) {
+		return new Region(offset, 0);
+	}
+
+	protected void selectRegion(IRegion region) throws ExecutionException {
+		selectRegions(new IRegion[] { region });
+	}
+
+	protected void selectRegions(IRegion[] regions) throws ExecutionException {
+		setBlockSelectionMode(false);
+
+		ISelection newSelection = new MultiTextSelection(document, regions);
+		textEditor.getSelectionProvider().setSelection(newSelection);
+	}
+
+	protected void selectIdentifierUnderCaret() throws ExecutionException {
+		int offset = getCaretOffset();
+
+		Region identifierRegion = getIdentifierUnderCaretRegion(offset);
+		if (identifierRegion != null)
+			selectRegion(identifierRegion);
+	}
+
+	protected boolean allRegionsHaveSameText() {
+		if (nothingSelected())
+			return false;
+		return allRegionsHaveSameText(getSelectedRegions());
+	}
+
+	private boolean allRegionsHaveSameText(IRegion[] regions) {
+		if (regions == null || regions.length == 1)
+			return true;
+
+		try {
+			return allRegionsHaveText(regions, regionAsString(regions[0]));
+		} catch (BadLocationException e) {
+			return false;
+		}
+	}
+
+	private boolean allRegionsHaveText(IRegion[] regions, String text) throws BadLocationException {
+		for (IRegion iRegion : regions) {
+			if (!text.equals(regionAsString(iRegion))) {
+				return false;
+			}
+		}
+		return true;
+	}
+
+	protected IRegion[] addRegion(IRegion[] regions, IRegion newRegion) {
+		if (newRegion != null) {
+			IRegion[] newRegions = Arrays.copyOf(regions, regions.length + 1);
+			newRegions[newRegions.length - 1] = newRegion;
+			return newRegions;
+		} else {
+			return regions;
+		}
+	}
+
+	protected IRegion[] removeLastRegionButOne(IRegion[] regions) {
+		if (regions == null || regions.length == 0)
+			return null;
+		if (regions.length == 1) {
+			return regions;
+		}
+
+		return Arrays.copyOf(regions, regions.length - 1);
+	}
+
+	protected int getCaretOffset() {
+		return getWidget().getCaretOffset();
+	}
+
+	protected void setCaretOffset(int offset) {
+		getWidget().setCaretOffset(offset);
+	}
+
+	protected IRegion findNextMatch(IRegion region) throws ExecutionException {
+		String fullText = getFullText();
+		try {
+			String searchString = getTextOfRegion(region);
+
+			int matchPos = fullText.indexOf(searchString, offsetAfter(region));
+			if (matchPos < 0)
+				return null;
+
+			return new Region(matchPos, region.getLength());
+		} catch (BadLocationException e) {
+			throw new ExecutionException("Internal error in findNextMatch", e);
+		}
+	}
+
+	protected IRegion[] findAllMatches(IRegion region) throws ExecutionException {
+		try {
+			String fullText = getFullText();
+			String searchString = getTextOfRegion(region);
+			List<IRegion> regions = findAllMatches(fullText, searchString);
+			return toArray(regions);
+		} catch (BadLocationException e) {
+			throw new ExecutionException("Internal error in findAllMatches", e);
+		}
+	}
+
+	private List<IRegion> findAllMatches(String fullText, String searchString) {
+		List<IRegion> regions = new ArrayList<>();
+		int length = searchString.length();
+		int matchPos = 0;
+		while ((matchPos = fullText.indexOf(searchString, matchPos)) >= 0) {
+			regions.add(new Region(matchPos, length));
+			matchPos += length;
+		}
+		return regions;
+	}
+
+	private boolean initFrom(ExecutionEvent event) {
+		this.event = event;
+		textEditor = getTextEditor(event);
+		if (textEditor == null)
+			return false;
+		document = getDocument();
+		return true;
+	}
+
+	private ITextEditor getTextEditor(ExecutionEvent event) {
+		IEditorPart editor = HandlerUtil.getActiveEditor(event);
+		return editor instanceof ITextEditor ? (ITextEditor) editor : null;
+	}
+
+	private IDocument getDocument() {
+		return textEditor.getDocumentProvider().getDocument(textEditor.getEditorInput());
+	}
+
+	private IRegion[] toArray(List<IRegion> regions) {
+		return regions.toArray(new IRegion[regions.size()]);
+	}
+
+	private int offsetAfter(IRegion region) {
+		return region.getOffset() + region.getLength();
+	}
+
+	private String getTextOfRegion(IRegion region) throws BadLocationException {
+		return document.get(region.getOffset(), region.getLength());
+	}
+
+	private String getFullText() {
+		return document.get();
+	}
+
+	private String regionAsString(IRegion region) throws BadLocationException {
+		return document.get(region.getOffset(), region.getLength());
+	}
+
+	private Region getIdentifierUnderCaretRegion(int offset) {
+		try {
+			int startOffset = findStartOfIdentifier(offset);
+			int endOffset = findEndOfIdentifier(startOffset);
+			Region identifierRegion = new Region(startOffset, endOffset - startOffset);
+			return identifierRegion;
+		} catch (BadLocationException e) {
+			return null;
+		}
+	}
+
+	private int findStartOfIdentifier(int offset) throws BadLocationException {
+		for (int i = offset - 1; i >= 0; i--) {
+			if (!isJavaIdentifierCharAtPos(i)) {
+				return i + 1;
+			}
+		}
+		return 0; // start of document reached
+	}
+
+	private int findEndOfIdentifier(int offset) throws BadLocationException {
+		for (int i = offset; i <= document.getLength(); i++) {
+			if (i == document.getLength() || !isJavaIdentifierCharAtPos(i)) {
+				return i;
+			}
+		}
+		return offset;
+	}
+
+	private boolean isJavaIdentifierCharAtPos(int i) throws BadLocationException {
+		return Character.isJavaIdentifierStart(document.getChar(i))
+				|| Character.isJavaIdentifierPart(document.getChar(i));
+	}
+
+	private StyledText getWidget() {
+		return (StyledText) textEditor.getAdapter(Control.class);
+	}
+
+	private void setBlockSelectionMode(boolean blockSelectionMode) {
+		if (!(textEditor instanceof ITextEditorExtension5)) {
+			return;
+		}
+		ITextEditorExtension5 ext = (ITextEditorExtension5) textEditor;
+		ext.setBlockSelectionMode(blockSelectionMode);
+	}
+}
diff --git a/org.eclipse.ui.workbench.texteditor/src/org/eclipse/ui/internal/texteditor/multiselection/AddAllMatchesToMultiSelectionHandler.java b/org.eclipse.ui.workbench.texteditor/src/org/eclipse/ui/internal/texteditor/multiselection/AddAllMatchesToMultiSelectionHandler.java
new file mode 100644
index 00000000000..b9d09fc7cf1
--- /dev/null
+++ b/org.eclipse.ui.workbench.texteditor/src/org/eclipse/ui/internal/texteditor/multiselection/AddAllMatchesToMultiSelectionHandler.java
@@ -0,0 +1,41 @@
+/*******************************************************************************
+ * Copyright (c) 2022 Dirk Steinkamp
+ *
+ * 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
+ *
+ * Contributors:
+ *     Dirk Steinkamp <dirk.steinkamp@gmx.de> - initial API and implementation
+ *******************************************************************************/
+ package org.eclipse.ui.internal.texteditor.multiselection;
+
+import org.eclipse.core.commands.ExecutionException;
+
+import org.eclipse.jface.text.IRegion;
+
+/**
+ * Handler to extend the current selection to all found matches in the document.
+ * If nothing is selected, an implicit selection of the word under the cursor is
+ * performed and the selection performed with this.
+ */
+public class AddAllMatchesToMultiSelectionHandler extends AbstractMultiSelectionHandler {
+
+	@Override
+	public void execute() throws ExecutionException {
+		if (nothingSelected()) {
+			selectIdentifierUnderCaret();
+		}
+		extendSelectionToAllMatches();
+	}
+
+	private void extendSelectionToAllMatches() throws ExecutionException {
+		if (allRegionsHaveSameText()) {
+			IRegion[] regions = getSelectedRegions();
+			selectRegions(findAllMatches(regions[0]));
+		}
+	}
+}
diff --git a/org.eclipse.ui.workbench.texteditor/src/org/eclipse/ui/internal/texteditor/multiselection/AddNextMatchToMultiSelectionHandler.java b/org.eclipse.ui.workbench.texteditor/src/org/eclipse/ui/internal/texteditor/multiselection/AddNextMatchToMultiSelectionHandler.java
new file mode 100644
index 00000000000..16f9d479d40
--- /dev/null
+++ b/org.eclipse.ui.workbench.texteditor/src/org/eclipse/ui/internal/texteditor/multiselection/AddNextMatchToMultiSelectionHandler.java
@@ -0,0 +1,43 @@
+/*******************************************************************************
+ * Copyright (c) 2022 Dirk Steinkamp
+ *
+ * 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
+ *
+ * Contributors:
+ *     Dirk Steinkamp <dirk.steinkamp@gmx.de> - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.ui.internal.texteditor.multiselection;
+
+import org.eclipse.core.commands.ExecutionException;
+
+import org.eclipse.jface.text.IRegion;
+
+/**
+ * Handler to extend the current selection to the next found match below the
+ * selection. If no word is selected, an implicit selection of the word under
+ * the cursor is performed.
+ */
+public class AddNextMatchToMultiSelectionHandler extends AbstractMultiSelectionHandler {
+
+	@Override
+	public void execute() throws ExecutionException {
+		if (nothingSelected()) {
+			selectIdentifierUnderCaret();
+		} else {
+			extendSelectionToNextMatch();
+		}
+	}
+
+	private void extendSelectionToNextMatch() throws ExecutionException {
+		if (allRegionsHaveSameText()) {
+			IRegion[] regions = getSelectedRegions();
+			IRegion nextMatch = findNextMatch(regions[regions.length - 1]);
+			selectRegions(addRegion(regions, nextMatch));
+		}
+	}
+}
diff --git a/org.eclipse.ui.workbench.texteditor/src/org/eclipse/ui/internal/texteditor/multiselection/RemoveLastMatchFromMultiSelectionHandler.java b/org.eclipse.ui.workbench.texteditor/src/org/eclipse/ui/internal/texteditor/multiselection/RemoveLastMatchFromMultiSelectionHandler.java
new file mode 100644
index 00000000000..35be36dd579
--- /dev/null
+++ b/org.eclipse.ui.workbench.texteditor/src/org/eclipse/ui/internal/texteditor/multiselection/RemoveLastMatchFromMultiSelectionHandler.java
@@ -0,0 +1,29 @@
+/*******************************************************************************
+ * Copyright (c) 2022 Dirk Steinkamp
+ *
+ * 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
+ *
+ * Contributors:
+ *     Dirk Steinkamp <dirk.steinkamp@gmx.de> - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.ui.internal.texteditor.multiselection;
+
+import org.eclipse.core.commands.ExecutionException;
+
+/**
+ * Removes last selection region from a multi-selection.
+ */
+public class RemoveLastMatchFromMultiSelectionHandler extends AbstractMultiSelectionHandler {
+
+	@Override
+	public void execute() throws ExecutionException {
+		if (allRegionsHaveSameText()) {
+			selectRegions(removeLastRegionButOne(getSelectedRegions()));
+		}
+	}
+}
diff --git a/org.eclipse.ui.workbench.texteditor/src/org/eclipse/ui/internal/texteditor/multiselection/StopMultiSelectionHandler.java b/org.eclipse.ui.workbench.texteditor/src/org/eclipse/ui/internal/texteditor/multiselection/StopMultiSelectionHandler.java
new file mode 100644
index 00000000000..fc28e7c922e
--- /dev/null
+++ b/org.eclipse.ui.workbench.texteditor/src/org/eclipse/ui/internal/texteditor/multiselection/StopMultiSelectionHandler.java
@@ -0,0 +1,37 @@
+/*******************************************************************************
+ * Copyright (c) 2022 Dirk Steinkamp
+ *
+ * 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
+ *
+ * Contributors:
+ *     Dirk Steinkamp <dirk.steinkamp@gmx.de> - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.ui.internal.texteditor.multiselection;
+
+import org.eclipse.core.commands.ExecutionException;
+
+/**
+ * Handler to stop multi-selection mode. If more than one selection is active,
+ * all selections are revoked, and the caret is positioned at position of the
+ * first caret.
+ */
+public class StopMultiSelectionHandler extends AbstractMultiSelectionHandler {
+
+	@Override
+	public void execute() throws ExecutionException {
+		if (isMultiSelectionActive()) {
+			stopMultiSelection();
+		}
+	}
+
+	private void stopMultiSelection() throws ExecutionException {
+		int caretOffset = getCaretOffset();
+		selectRegion(offsetAsCaretRegion(caretOffset));
+		setCaretOffset(caretOffset);
+	}
+}