新增SingleLiveEvent

tools/build.gradle

@@ -42,7 +42,7 @@ repositories {
 
 
 group 'com.qmai.android.tools'
-version '1.1.8-SNAPSHOT'
+version '1.1.9-SNAPSHOT'
 
 gradlePublish {
 

tools/src/main/java/com/qimai/android/tools/SingleLiveEvent.java

+package com.qimai.android.tools;
+
+import android.util.Log;
+
+import androidx.annotation.MainThread;
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.lifecycle.LifecycleOwner;
+import androidx.lifecycle.MutableLiveData;
+import androidx.lifecycle.Observer;
+
+import org.jetbrains.annotations.NotNull;
+
+import java.util.concurrent.atomic.AtomicBoolean;
+
+public class SingleLiveEvent<T> extends MutableLiveData<T> {
+
+    private static final String TAG = "SingleLiveEvent";
+
+    private final AtomicBoolean mPending = new AtomicBoolean(false);
+
+    @Override
+    public void observe(@NonNull @NotNull LifecycleOwner owner, @NonNull @NotNull final Observer<? super T> observer) {
+        if (hasActiveObservers()) {
+            Log.w(TAG, "Multiple observers registered but only one will be notified of changes.");
+        }
+
+        // Observe the internal MutableLiveData
+        super.observe(owner, new Observer<T>() {
+            @Override
+            public void onChanged(@Nullable T t) {
+                if (mPending.compareAndSet(true, false)) {
+                    observer.onChanged(t);
+                }
+            }
+        });
+    }
+
+
+
+    @MainThread
+    public void setValue(@Nullable T t) {
+        mPending.set(true);
+        super.setValue(t);
+    }
+
+    /**
+     * Used for cases where T is Void, to make calls cleaner.
+     */
+    @MainThread
+    public void call() {
+        setValue(null);
+    }
+}
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