Expose nextToUndo, nextToRedo in public API. Requires to make UndoMan…

…ager generic.
FXMisc · Apr 28, 2017 · 2eedd39 · 2eedd39
1 parent be4d813
commit 2eedd39
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Showing 5 changed files with 50 additions and 28 deletions.
diff --git a/undofx-demos/src/main/java/org/fxmisc/undo/demo/CircleProperties.java b/undofx-demos/src/main/java/org/fxmisc/undo/demo/CircleProperties.java
@@ -173,7 +173,7 @@ public boolean equals(Object other) {
     private final Button redoBtn = new Button("Redo");
     private final Button saveBtn = new Button("Save");
     private final EventStream<CircleChange<?>> changes;
-    private final UndoManager undoManager;
+    private final UndoManager<CircleChange<?>> undoManager;
 
     {
         circle.fillProperty().bind(colorPicker.valueProperty());

diff --git a/undofx/src/main/java/org/fxmisc/undo/UndoManager.java b/undofx/src/main/java/org/fxmisc/undo/UndoManager.java
@@ -4,7 +4,7 @@
 
 import org.reactfx.value.Val;
 
-public interface UndoManager {
+public interface UndoManager<C> {
 
     /**
      * Represents a position in UndoManager's history.
@@ -48,6 +48,18 @@ interface UndoPosition {
     Val<Boolean> undoAvailableProperty();
     boolean isUndoAvailable();
 
+    /**
+     * Gives a peek at the change that will be undone by {@link #undo()}.
+     */
+    Val<C> nextToUndoProperty();
+    default C getNextToUndo() { return nextToUndoProperty().getValue(); }
+
+    /**
+     * Gives a peek at the change that will be redone by {@link #redo()}.
+     */
+    Val<C> nextToRedoProperty();
+    default C getNextToRedo() { return nextToRedoProperty().getValue(); }
+
     /**
      * Indicates whether there is a change that can be redone.
      */

diff --git a/undofx/src/main/java/org/fxmisc/undo/UndoManagerFactory.java b/undofx/src/main/java/org/fxmisc/undo/UndoManagerFactory.java
@@ -26,7 +26,7 @@ public interface UndoManagerFactory {
      *              describes an action to be performed. Calling {@code apply.accept(c)}
      *              <em>must</em> cause {@code c} to be emitted from {@code changeStream}.
      */
-    default <C> UndoManager create(
+    default <C> UndoManager<C> create(
             EventStream<C> changeStream,
             Function<? super C, ? extends C> invert,
             Consumer<C> apply) {
@@ -46,7 +46,7 @@ default <C> UndoManager create(
      * @param merge Used to merge two subsequent changes into one.
      *              Returns an empty {@linkplain Optional} when the changes cannot or should not be merged.
      */
-    default <C> UndoManager create(
+    default <C> UndoManager<C> create(
             EventStream<C> changeStream,
             Function<? super C, ? extends C> invert,
             Consumer<C> apply,
@@ -72,7 +72,7 @@ default <C> UndoManager create(
      * @param isIdentity returns true for changes whose application would have no effect, thereby equivalent
      *                   to an identity function ({@link Function#identity()}) on the underlying model.
      */
-    <C> UndoManager create(
+    <C> UndoManager<C> create(
             EventStream<C> changeStream,
             Function<? super C, ? extends C> invert,
             Consumer<C> apply,
@@ -84,7 +84,7 @@ <C> UndoManager create(
      *
      * For description of parameters, see {@link #create(EventStream, Function, Consumer)}.
      */
-    public static <C> UndoManager unlimitedHistoryUndoManager(
+    public static <C> UndoManager<C> unlimitedHistoryUndoManager(
             EventStream<C> changeStream,
             Function<? super C, ? extends C> invert,
             Consumer<C> apply) {
@@ -96,7 +96,7 @@ public static <C> UndoManager unlimitedHistoryUndoManager(
      *
      * For description of parameters, see {@link #create(EventStream, Function, Consumer, BiFunction)}.
      */
-    public static <C> UndoManager unlimitedHistoryUndoManager(
+    public static <C> UndoManager<C> unlimitedHistoryUndoManager(
             EventStream<C> changeStream,
             Function<? super C, ? extends C> invert,
             Consumer<C> apply,
@@ -108,7 +108,7 @@ public static <C> UndoManager unlimitedHistoryUndoManager(
      *
      * For description of parameters, see {@link #create(EventStream, Function, Consumer, BiFunction, Predicate)}.
      */
-    public static <C> UndoManager unlimitedHistoryUndoManager(
+    public static <C> UndoManager<C> unlimitedHistoryUndoManager(
             EventStream<C> changeStream,
             Function<? super C, ? extends C> invert,
             Consumer<C> apply,
@@ -124,7 +124,7 @@ public static <C> UndoManager unlimitedHistoryUndoManager(
     public static UndoManagerFactory unlimitedHistoryFactory() {
         return new UndoManagerFactory() {
             @Override
-            public <C> UndoManager create(
+            public <C> UndoManager<C> create(
                     EventStream<C> changeStream,
                     Function<? super C, ? extends C> invert,
                     Consumer<C> apply,
@@ -143,7 +143,7 @@ public <C> UndoManager create(
      *
      * @param capacity maximum number of changes the returned UndoManager can store
      */
-    public static <C> UndoManager fixedSizeHistoryUndoManager(
+    public static <C> UndoManager<C> fixedSizeHistoryUndoManager(
             EventStream<C> changeStream,
             Function<? super C, ? extends C> invert,
             Consumer<C> apply,
@@ -159,7 +159,7 @@ public static <C> UndoManager fixedSizeHistoryUndoManager(
      *
      * @param capacity maximum number of changes the returned UndoManager can store
      */
-    public static <C> UndoManager fixedSizeHistoryUndoManager(
+    public static <C> UndoManager<C> fixedSizeHistoryUndoManager(
             EventStream<C> changeStream,
             Function<? super C, ? extends C> invert,
             Consumer<C> apply,
@@ -176,7 +176,7 @@ public static <C> UndoManager fixedSizeHistoryUndoManager(
      *
      * @param capacity maximum number of changes the returned UndoManager can store
      */
-    public static <C> UndoManager fixedSizeHistoryUndoManager(
+    public static <C> UndoManager<C> fixedSizeHistoryUndoManager(
             EventStream<C> changeStream,
             Function<? super C, ? extends C> invert,
             Consumer<C> apply,
@@ -194,7 +194,7 @@ public static <C> UndoManager fixedSizeHistoryUndoManager(
     public static UndoManagerFactory fixedSizeHistoryFactory(int capacity) {
         return new UndoManagerFactory() {
             @Override
-            public <C> UndoManager create(
+            public <C> UndoManager<C> create(
                     EventStream<C> changeStream,
                     Function<? super C, ? extends C> invert,
                     Consumer<C> apply,
@@ -213,7 +213,7 @@ public <C> UndoManager create(
      * {@link UndoManager#atMarkedPositionProperty()} to determine whether any change has occurred since the last
      * {@link UndoManager#mark()} (e.g. since the last save).
      */
-    public static <C> UndoManager zeroHistoryUndoManager(EventStream<C> changeStream) {
+    public static <C> UndoManager<C> zeroHistoryUndoManager(EventStream<C> changeStream) {
         ChangeQueue<C> queue = new ZeroSizeChangeQueue<>();
         return new UndoManagerImpl<>(queue, c -> c, c -> {}, (c1, c2) -> Optional.empty(), c -> false, changeStream);
     }
@@ -226,7 +226,7 @@ public static <C> UndoManager zeroHistoryUndoManager(EventStream<C> changeStream
     public static UndoManagerFactory zeroHistoryFactory() {
         return new UndoManagerFactory() {
             @Override
-            public <C> UndoManager create(
+            public <C> UndoManager<C> create(
                     EventStream<C> changeStream,
                     Function<? super C, ? extends C> invert,
                     Consumer<C> apply,

diff --git a/undofx/src/main/java/org/fxmisc/undo/impl/UndoManagerImpl.java b/undofx/src/main/java/org/fxmisc/undo/impl/UndoManagerImpl.java
@@ -18,7 +18,7 @@
 import org.reactfx.value.Val;
 import org.reactfx.value.ValBase;
 
-public class UndoManagerImpl<C> implements UndoManager {
+public class UndoManagerImpl<C> implements UndoManager<C> {
 
     private class UndoPositionImpl implements UndoPosition {
         private final QueuePosition queuePos;
@@ -118,6 +118,16 @@ public boolean redo() {
         }
     }
 
+    @Override
+    public Val<C> nextToUndoProperty() {
+        return nextToUndo;
+    }
+
+    @Override
+    public Val<C> nextToRedoProperty() {
+        return nextToRedo;
+    }
+
     @Override
     public boolean isUndoAvailable() {
         return nextToUndo.isPresent();

diff --git a/undofx/src/test/java/org/fxmisc/undo/impl/UndoManagerTest.java b/undofx/src/test/java/org/fxmisc/undo/impl/UndoManagerTest.java
@@ -20,7 +20,7 @@ public class UndoManagerTest {
     public void testUndoInvertsTheChange() {
         EventSource<Integer> changes = new EventSource<>();
         Var<Integer> lastAction = Var.newSimpleVar(null);
-        UndoManager um = UndoManagerFactory.unlimitedHistoryUndoManager(
+        UndoManager<?> um = UndoManagerFactory.unlimitedHistoryUndoManager(
                 changes, i -> -i, i -> { lastAction.setValue(i); changes.push(i); });
 
         changes.push(3);
@@ -43,7 +43,7 @@ public void testUndoInvertsTheChange() {
     @Test
     public void testMark() {
         EventSource<Integer> changes = new EventSource<>();
-        UndoManager um = UndoManagerFactory.fixedSizeHistoryUndoManager(
+        UndoManager<?> um = UndoManagerFactory.fixedSizeHistoryUndoManager(
                 changes, c -> c, changes::push, 4);
 
         assertTrue(um.atMarkedPositionProperty().get());
@@ -68,7 +68,7 @@ public void testMark() {
     @Test
     public void testPositionValidAfterAddingAChange() {
         EventSource<Integer> changes = new EventSource<>();
-        UndoManager um = UndoManagerFactory.unlimitedHistoryUndoManager(changes, c -> c, changes::push);
+        UndoManager<?> um = UndoManagerFactory.unlimitedHistoryUndoManager(changes, c -> c, changes::push);
 
         changes.push(1);
         UndoPosition pos = um.getCurrentPosition();
@@ -79,7 +79,7 @@ public void testPositionValidAfterAddingAChange() {
     @Test
     public void testPositionInvalidAfterMerge() {
         EventSource<Integer> changes = new EventSource<>();
-        UndoManager um = UndoManagerFactory.unlimitedHistoryUndoManager(
+        UndoManager<?> um = UndoManagerFactory.unlimitedHistoryUndoManager(
                 changes, c -> -c, changes::push, (c1, c2) -> Optional.of(c1 + c2));
 
         changes.push(1);
@@ -91,7 +91,7 @@ public void testPositionInvalidAfterMerge() {
     @Test
     public void testRedoUnavailableAfterAnnihilation() {
         EventSource<Integer> changes = new EventSource<>();
-        UndoManager um = UndoManagerFactory.unlimitedHistoryUndoManager(
+        UndoManager<?> um = UndoManagerFactory.unlimitedHistoryUndoManager(
                 changes, c -> -c, changes::push, (c1, c2) -> Optional.of(c1 + c2), c -> c == 0);
 
         changes.push(1);
@@ -102,7 +102,7 @@ public void testRedoUnavailableAfterAnnihilation() {
     @Test
     public void zeroHistoryUndoManagerMark() {
         EventSource<Integer> changes = new EventSource<>();
-        UndoManager um = UndoManagerFactory.zeroHistoryUndoManager(changes);
+        UndoManager<?> um = UndoManagerFactory.zeroHistoryUndoManager(changes);
 
         assertTrue(um.atMarkedPositionProperty().get());
         changes.push(1);
@@ -122,7 +122,7 @@ public void zeroHistoryUndoManagerMark() {
     @Test
     public void testAtMarkedPositionRevalidation() {
         EventSource<Integer> changes = new EventSource<>();
-        UndoManager um = UndoManagerFactory.zeroHistoryUndoManager(changes);
+        UndoManager<?> um = UndoManagerFactory.zeroHistoryUndoManager(changes);
 
         um.atMarkedPositionProperty().get(); // atMarkedPositionProperty is now valid
 
@@ -142,7 +142,7 @@ public void testAtMarkedPositionRevalidation() {
     @Test(expected = IllegalStateException.class)
     public void testFailFastWhenExpectedChangeNotReceived() {
         EventSource<Integer> changes = new EventSource<>();
-        UndoManager um = UndoManagerFactory.unlimitedHistoryUndoManager(
+        UndoManager<?> um = UndoManagerFactory.unlimitedHistoryUndoManager(
                 changes, i -> -i, i -> {});
 
         changes.push(1);
@@ -156,7 +156,7 @@ public void testFailFastWhenExpectedChangeNotReceived() {
     public void testPushedNonIdentityChangeIsStored() {
         SimpleIntegerProperty lastAppliedValue = new SimpleIntegerProperty(0);
         EventSource<Integer> changes = new EventSource<>();
-        UndoManager um = UndoManagerFactory.unlimitedHistoryUndoManager(
+        UndoManager<?> um = UndoManagerFactory.unlimitedHistoryUndoManager(
                 changes,
                 i -> -i,    // invert
                 i -> { lastAppliedValue.set(i); changes.push(i); }, // apply change and re-emit value so expected change is received
@@ -174,7 +174,7 @@ public void testPushedNonIdentityChangeIsStored() {
     public void testPushedIdentityChangeIsNotStored() {
         SimpleIntegerProperty lastAppliedValue = new SimpleIntegerProperty(0);
         EventSource<Integer> changes = new EventSource<>();
-        UndoManager um = UndoManagerFactory.unlimitedHistoryUndoManager(
+        UndoManager<?> um = UndoManagerFactory.unlimitedHistoryUndoManager(
                 changes,
                 i -> -i,    // invert
                 i -> { lastAppliedValue.set(i); changes.push(i); }, // apply change and re-emit value so expected change is received
@@ -195,7 +195,7 @@ public void testPushedIdentityChangeIsNotStored() {
     public void testMergeResultingInIdentityChangeAnnihilatesBothAndPreventsNextMerge() {
         SimpleIntegerProperty lastAppliedValue = new SimpleIntegerProperty(0);
         EventSource<Integer> changes = new EventSource<>();
-        UndoManager um = UndoManagerFactory.unlimitedHistoryUndoManager(
+        UndoManager<?> um = UndoManagerFactory.unlimitedHistoryUndoManager(
                 changes,
                 i -> -i,    // invert
                 i -> { lastAppliedValue.set(i); changes.push(i); }, // apply change and re-emit value so expected change is received
@@ -229,7 +229,7 @@ public void testMergeResultingInIdentityChangeAnnihilatesBothAndPreventsNextMerg
     public void testMergeResultingInNonIdentityChangeStoresMergeAndPreventsNextMerge() {
         SimpleIntegerProperty lastAppliedValue = new SimpleIntegerProperty(0);
         EventSource<Integer> changes = new EventSource<>();
-        UndoManager um = UndoManagerFactory.unlimitedHistoryUndoManager(
+        UndoManager<?> um = UndoManagerFactory.unlimitedHistoryUndoManager(
                 changes,
                 i -> -i,    // invert
                 i -> { lastAppliedValue.set(i); changes.push(i); }, // apply change and re-emit value so expected change is received