Image Editor - Allow undoing during croping.

src/org/thoughtcrime/securesms/imageeditor/model/EditorFlags.java

@@ -1,5 +1,7 @@
 package org.thoughtcrime.securesms.imageeditor.model;
 
+import android.support.annotation.NonNull;
+
 /**
  * Flags for an {@link EditorElement}.
  * <p>
@@ -113,4 +115,9 @@ public final class EditorFlags {
   void restoreState(int flags) {
     this.flags = flags;
   }
+
+  public void set(@NonNull EditorFlags from) {
+    this.persistedFlags = from.persistedFlags;
+    this.flags = from.flags;
+  }
 }

src/org/thoughtcrime/securesms/imageeditor/model/EditorModel.java

@@ -40,8 +40,8 @@ public final class EditorModel implements Parcelable, RendererContext.Ready {
   @NonNull
   private Runnable invalidate = NULL_RUNNABLE;
 
-  private final ElementStack undoStack;
+  private final UndoRedoStacks undoRedoStacks;
-  private final ElementStack redoStack;
+  private final UndoRedoStacks cropUndoRedoStacks;
 
   private EditorElementHierarchy editorElementHierarchy;
 
@@ -51,16 +51,16 @@ public final class EditorModel implements Parcelable, RendererContext.Ready {
   public EditorModel() {
     this.size                   = new Point(1024, 1024);
     this.editorElementHierarchy = EditorElementHierarchy.create();
-    this.undoStack              = new ElementStack(50);
+    this.undoRedoStacks         = new UndoRedoStacks(50);
-    this.redoStack              = new ElementStack(50);
+    this.cropUndoRedoStacks     = new UndoRedoStacks(50);
   }
 
   private EditorModel(Parcel in) {
     ClassLoader classLoader     = getClass().getClassLoader();
     this.size                   = new Point(in.readInt(), in.readInt());
     this.editorElementHierarchy = EditorElementHierarchy.create(in.readParcelable(classLoader));
-    this.undoStack              = in.readParcelable(classLoader);
+    this.undoRedoStacks         = in.readParcelable(classLoader);
-    this.redoStack              = in.readParcelable(classLoader);
+    this.cropUndoRedoStacks     = in.readParcelable(classLoader);
   }
 
   public void setInvalidate(@Nullable Runnable invalidate) {
@@ -107,28 +107,35 @@ public final class EditorModel implements Parcelable, RendererContext.Ready {
   }
 
   public void pushUndoPoint() {
-    if (undoStack.tryPush(editorElementHierarchy.getRoot())) {
+    UndoRedoStacks stacks = isCropping() ? cropUndoRedoStacks : undoRedoStacks;
-      redoStack.clear();
+
+    if (stacks.getUndoStack().tryPush(editorElementHierarchy.getRoot())) {
+      stacks.getRedoStack().clear();
     }
   }
 
   public void undo() {
-    undoRedo(undoStack, redoStack);
+    boolean        cropping = isCropping();
+    UndoRedoStacks stacks   = cropping ? cropUndoRedoStacks : undoRedoStacks;
+
+    undoRedo(stacks.getUndoStack(), stacks.getRedoStack(), cropping);
   }
 
   public void redo() {
-    undoRedo(redoStack, undoStack);
+    boolean        cropping = isCropping();
+    UndoRedoStacks stacks   = cropping ? cropUndoRedoStacks : undoRedoStacks;
+
+    undoRedo(stacks.getRedoStack(), stacks.getUndoStack(), cropping);
   }
 
-  private void undoRedo(@NonNull ElementStack fromStack, @NonNull ElementStack toStack) {
+  private void undoRedo(@NonNull ElementStack fromStack, @NonNull ElementStack toStack, boolean keepEditorState) {
     final EditorElement popped = fromStack.pop();
-
     if (popped != null) {
       EditorElement oldRootElement = editorElementHierarchy.getRoot();
       editorElementHierarchy = EditorElementHierarchy.create(popped);
       toStack.tryPush(oldRootElement);
 
-      restoreStateWithAnimations(oldRootElement, editorElementHierarchy.getRoot(), invalidate);
+      restoreStateWithAnimations(oldRootElement, editorElementHierarchy.getRoot(), invalidate, keepEditorState);
       invalidate.run();
 
       // re-zoom image root as the view port might be different now
@@ -136,7 +143,7 @@ public final class EditorModel implements Parcelable, RendererContext.Ready {
     }
   }
 
-  private static void restoreStateWithAnimations(@NonNull EditorElement fromRootElement, @NonNull EditorElement toRootElement, @NonNull Runnable onInvalidate) {
+  private static void restoreStateWithAnimations(@NonNull EditorElement fromRootElement, @NonNull EditorElement toRootElement, @NonNull Runnable onInvalidate, boolean keepEditorState) {
     Map<UUID, EditorElement> fromMap = getElementMap(fromRootElement);
     Map<UUID, EditorElement> toMap = getElementMap(toRootElement);
 
@@ -145,6 +152,11 @@ public final class EditorModel implements Parcelable, RendererContext.Ready {
       EditorElement toElement = toMap.get(fromElement.getId());
       if (toElement != null) {
         toElement.animateFrom(fromElement.getLocalMatrixAnimating(), onInvalidate);
+
+        if (keepEditorState) {
+          toElement.getEditorMatrix().set(fromElement.getEditorMatrix());
+          toElement.getFlags().set(fromElement.getFlags());
+        }
       } else {
         // element is removed
         EditorElement parentFrom = fromRootElement.parentOf(fromElement);
@@ -173,6 +185,8 @@ public final class EditorModel implements Parcelable, RendererContext.Ready {
 
   public void startCrop() {
     pushUndoPoint();
+    cropUndoRedoStacks.getUndoStack().clear();
+    cropUndoRedoStacks.getUndoStack().clear();
     editorElementHierarchy.startCrop(invalidate);
   }
 
@@ -236,8 +250,8 @@ public final class EditorModel implements Parcelable, RendererContext.Ready {
     dest.writeInt(size.x);
     dest.writeInt(size.y);
     dest.writeParcelable(editorElementHierarchy.getRoot(), flags);
-    dest.writeParcelable(undoStack, flags);
+    dest.writeParcelable(undoRedoStacks, flags);
-    dest.writeParcelable(redoStack, flags);
+    dest.writeParcelable(cropUndoRedoStacks, flags);
   }
 
   /**
@@ -337,11 +351,12 @@ public final class EditorModel implements Parcelable, RendererContext.Ready {
     parent.addElement(element);
 
     if (parent != mainImage) {
-      undoStack.clear();
+      undoRedoStacks.getUndoStack().clear();
     }
   }
 
   public boolean isChanged() {
+    ElementStack undoStack = undoRedoStacks.getUndoStack();
     return !undoStack.isEmpty() || undoStack.isOverflowed();
   }
 
@@ -381,7 +396,7 @@ public final class EditorModel implements Parcelable, RendererContext.Ready {
     editorElementHierarchy.flipRotate(0, -1, 1, visibleViewPort, invalidate);
   }
 
-  public void flipVerticle() {
+  public void flipVertical() {
     pushUndoPoint();
     editorElementHierarchy.flipRotate(0, 1, -1, visibleViewPort, invalidate);
   }

src/org/thoughtcrime/securesms/imageeditor/model/UndoRedoStacks.java

@@ -0,0 +1,53 @@
+package org.thoughtcrime.securesms.imageeditor.model;
+
+import android.os.Parcel;
+import android.os.Parcelable;
+
+final class UndoRedoStacks implements Parcelable {
+
+  private final ElementStack undoStack;
+  private final ElementStack redoStack;
+
+  public UndoRedoStacks(int limit) {
+    this(new ElementStack(limit), new ElementStack(limit));
+  }
+
+  private UndoRedoStacks(ElementStack undoStack, ElementStack redoStack) {
+    this.undoStack = undoStack;
+    this.redoStack = redoStack;
+  }
+
+  public static final Creator<UndoRedoStacks> CREATOR = new Creator<UndoRedoStacks>() {
+    @Override
+    public UndoRedoStacks createFromParcel(Parcel in) {
+      return new UndoRedoStacks(
+      in.readParcelable(ElementStack.class.getClassLoader()),
+      in.readParcelable(ElementStack.class.getClassLoader())
+      );
+    }
+
+    @Override
+    public UndoRedoStacks[] newArray(int size) {
+      return new UndoRedoStacks[size];
+    }
+  };
+
+  @Override
+  public void writeToParcel(Parcel dest, int flags) {
+    dest.writeParcelable(undoStack, flags);
+    dest.writeParcelable(redoStack, flags);
+  }
+
+  @Override
+  public int describeContents() {
+    return 0;
+  }
+
+  ElementStack getUndoStack() {
+    return undoStack;
+  }
+
+  ElementStack getRedoStack() {
+    return redoStack;
+  }
+}

src/org/thoughtcrime/securesms/scribbles/ImageEditorHud.java

@@ -107,7 +107,7 @@ public final class ImageEditorHud extends LinearLayout {
 
     setVisibleViewsWhenInMode(Mode.MOVE_DELETE, confirmButton, deleteButton);
 
-    setVisibleViewsWhenInMode(Mode.CROP, confirmButton, cropFlipButton, cropRotateButton, cropAspectLock);
+    setVisibleViewsWhenInMode(Mode.CROP, confirmButton, cropFlipButton, cropRotateButton, cropAspectLock, undoButton);
 
     for (Set<View> views : visibilityModeMap.values()) {
       allViews.addAll(views);