Merge pull request #28 from R3PI/develop

Develop

CHANGELOG.md

@@ -1,6 +1,11 @@
 Change Log
 ==========
 
+Version 1.0.0
+----------------------------
+ * Added safe operations helper class.
+ * Fixed issue where ConcurrentModificationException would occur when removing listeners while traversing the listener list.
+
 Version 0.9.0
 ----------------------------
  * Removed deprecated code.

README.md

@@ -9,7 +9,7 @@ Defrag is available in the jCenter repository:
 
 ```java
 dependencies {
-  compile 'com.solera.defrag:defrag:0.9.0'
+  compile 'com.solera.defrag:defrag:1.0.0'
 }
 ```
 

build.gradle

@@ -5,7 +5,7 @@ buildscript {
     jcenter()
   }
   dependencies {
-    classpath 'com.android.tools.build:gradle:2.1.3'
+    classpath 'com.android.tools.build:gradle:2.2.1'
     classpath 'com.neenbedankt.gradle.plugins:android-apt:1.8'
     classpath 'com.jfrog.bintray.gradle:gradle-bintray-plugin:1.6'
     classpath 'com.github.dcendents:android-maven-gradle-plugin:1.4.1'

defrag/build.gradle

@@ -4,7 +4,7 @@ apply plugin: 'com.github.dcendents.android-maven'
 apply plugin: 'android-apt'
 
 group = 'com.solera.defrag'
-version = '0.9.0'
+version = '1.0.0'
 
 
 android {

defrag/src/main/java/com/solera/defrag/ViewStack.java

@@ -44,6 +44,7 @@
 import java.util.Deque;
 import java.util.Iterator;
 import java.util.List;
+import java.util.concurrent.CopyOnWriteArrayList;
 
 import auto.parcel.AutoParcel;
 
@@ -55,7 +56,7 @@ public class ViewStack extends FrameLayout {
 	public static final Bundle USE_EXISTING_SAVED_STATE = new Bundle();
 	private static final int DEFAULT_ANIMATION_DURATION_IN_MS = 300;
 	private static final String SINGLE_PARAMETER_KEY = "view_stack_single_param";
-	private final Collection<ViewStackListener> viewStackListeners = new ArrayList<>();
+	private final Collection<ViewStackListener> viewStackListeners = new CopyOnWriteArrayList<>();
 	private final Deque<ViewStackEntry> viewStack = new ArrayDeque<>();
 	private TraversingState traversingState = TraversingState.IDLE;
 	private Object result;
@@ -129,10 +130,12 @@ public void onMeasured(View view, int width, int height) {
 	}
 
 	public void addTraversingListener(@NonNull ViewStackListener listener) {
+		ViewUtils.verifyMainThread();
 		viewStackListeners.add(listener);
 	}
 
 	public void removeTraversingListener(@NonNull ViewStackListener listener) {
+		ViewUtils.verifyMainThread();
 		viewStackListeners.remove(listener);
 	}
 

defrag/src/main/java/com/solera/defrag/ViewStackUtils.java

@@ -0,0 +1,144 @@
+package com.solera.defrag;
+
+import android.os.Bundle;
+import android.support.annotation.LayoutRes;
+import android.support.annotation.MainThread;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.support.v4.util.Pair;
+import java.util.List;
+
+/**
+ * A collection of utilities for ViewStacks.
+ */
+public class ViewStackUtils {
+	private ViewStackUtils() {
+	}
+
+	/**
+	 * Safely replace the current view as soon as the {@link ViewStack} will be in {@link
+	 * TraversingState#IDLE}. If it is already in the idle state, method is invoked immediately.
+	 */
+	public static void safeReplace(@NonNull final ViewStack viewStack, @LayoutRes int layout) {
+		safeReplaceWithParameters(viewStack, layout, null);
+	}
+
+	/**
+	 * Safely replace the current view as soon as the {@link ViewStack} will be in {@link
+	 * TraversingState#IDLE}. If it is already in the idle state, method is invoked immediately.
+	 */
+	public static void safeReplaceWithParameters(@NonNull final ViewStack viewStack,
+			@LayoutRes final int layout, @Nullable final Bundle parameters) {
+		waitForTraversingState(viewStack, TraversingState.IDLE, new ViewStackListener() {
+			@Override
+			public void onTraversing(@NonNull TraversingState traversingState) {
+				viewStack.replaceWithParameters(layout, parameters);
+			}
+		});
+	}
+
+	/**
+	 * Safely replace the {@link ViewStack} stack as soon as the {@link ViewStack} will be in {@link
+	 * TraversingState#IDLE}. If it is already in the idle state, method is invoked immediately.
+	 */
+	public static void safeReplaceStack(@NonNull final ViewStack viewStack,
+			@NonNull final List<Pair<Integer, Bundle>> views) {
+		waitForTraversingState(viewStack, TraversingState.IDLE, new ViewStackListener() {
+			@Override
+			public void onTraversing(@NonNull TraversingState traversingState) {
+				viewStack.replaceStack(views);
+			}
+		});
+	}
+
+	/**
+	 * Safely push a view (as soon as the {@link ViewStack} will be in {@link TraversingState#IDLE},
+	 * if it is already in the idle state, method is invoked immediately).
+	 */
+	public static void safePush(@NonNull final ViewStack viewStack, @LayoutRes int layout) {
+		safePushWithParameters(viewStack, layout, null);
+	}
+
+	/**
+	 * Safely push a view as soon as the {@link ViewStack} will be in {@link TraversingState#IDLE}.
+	 * If it is already in the idle state, method is invoked immediately.
+	 */
+	public static void safePushWithParameters(@NonNull final ViewStack viewStack,
+			@LayoutRes final int layout, @Nullable final Bundle parameters) {
+		waitForTraversingState(viewStack, TraversingState.IDLE, new ViewStackListener() {
+			@Override
+			public void onTraversing(@NonNull TraversingState traversingState) {
+				viewStack.pushWithParameters(layout, parameters);
+			}
+		});
+	}
+
+	/**
+	 * Safely pop the current view as soon as the {@link ViewStack} will be in {@link
+	 * TraversingState#IDLE}. If it is already in the idle state, method is invoked immediately.
+	 * <p>
+	 * Note: You cannot be sure if the pop operation has been successful.
+	 */
+	public static void safePop(@NonNull final ViewStack viewStack) {
+		safePopWithResult(viewStack, null);
+	}
+
+	/**
+	 * Safely pop the current view as soon as the {@link ViewStack} will be in {@link
+	 * TraversingState#IDLE}. If it is already in the idle state, method is invoked immediately.
+	 * <p>
+	 * Note: You cannot be sure if the pop operation has been successful.
+	 */
+	public static void safePopWithResult(@NonNull final ViewStack viewStack,
+			@Nullable final Object result) {
+		waitForTraversingState(viewStack, TraversingState.IDLE, new ViewStackListener() {
+			@Override
+			public void onTraversing(@NonNull TraversingState traversingState) {
+				viewStack.popWithResult(result);
+			}
+		});
+	}
+
+	/**
+	 * Safely pop to the given view layout as soon as the {@link ViewStack} will be in {@link
+	 * TraversingState#IDLE}. If it is already in the idle state, method is invoked immediately.
+	 * <p>
+	 * Note: You cannot be sure if the pop operation has been successful.
+	 */
+	public static void safePopBackToWithResult(@NonNull final ViewStack viewStack,
+			@LayoutRes final int layout, @Nullable final Object result) {
+		waitForTraversingState(viewStack, TraversingState.IDLE, new ViewStackListener() {
+			@Override
+			public void onTraversing(@NonNull TraversingState traversingState) {
+				viewStack.popBackToWithResult(layout, result);
+			}
+		});
+	}
+
+	/**
+	 * Call the given callback when viewStack will be in the given state (if it is already in the
+	 * given state, the callback is immediately invoked).
+	 *
+	 * @param viewStack the viewStack to wait on
+	 * @param desiredState the traversing state to wait on
+	 * @param callback the callback to invoke
+	 */
+	@MainThread
+	private static void waitForTraversingState(@NonNull final ViewStack viewStack,
+			@NonNull final TraversingState desiredState, @NonNull final ViewStackListener callback) {
+		ViewUtils.verifyMainThread();
+		if (desiredState == viewStack.getTraversingState()) {
+			callback.onTraversing(desiredState);
+		} else {
+			viewStack.addTraversingListener(new ViewStackListener() {
+				@Override
+				public void onTraversing(@NonNull TraversingState traversingState) {
+					if (traversingState == desiredState) {
+						viewStack.removeTraversingListener(this);
+						callback.onTraversing(desiredState);
+					}
+				}
+			});
+		}
+	}
+}

defrag/src/main/java/com/solera/defrag/ViewUtils.java

@@ -18,6 +18,7 @@
  */
 package com.solera.defrag;
 
+import android.os.Looper;
 import android.support.annotation.MainThread;
 import android.support.annotation.NonNull;
 import android.view.View;
@@ -30,6 +31,18 @@ public class ViewUtils {
   private ViewUtils() {
   }
 
+  /**
+   * Verify that the calling thread is the Android main thread.
+   *
+   * @throws IllegalStateException when called from any other thread.
+   */
+  public static void verifyMainThread() {
+    if (Looper.myLooper() != Looper.getMainLooper()) {
+      throw new IllegalStateException(
+          "Expected to be called on the main thread but was " + Thread.currentThread().getName());
+    }
+  }
+
   /**
    * Call the given callback when the view has been measured (if it has already been measured, the
    * callback is immediately invoked.