diff --git a/twidere.component.common/src/main/java/org/mariotaku/twidere/model/Tab.java b/twidere.component.common/src/main/java/org/mariotaku/twidere/model/Tab.java
index 658419cf5..041434488 100644
--- a/twidere.component.common/src/main/java/org/mariotaku/twidere/model/Tab.java
+++ b/twidere.component.common/src/main/java/org/mariotaku/twidere/model/Tab.java
@@ -45,9 +45,6 @@ import org.mariotaku.twidere.model.util.TabArgumentsFieldConverter;
 import org.mariotaku.twidere.model.util.TabExtrasFieldConverter;
 import org.mariotaku.twidere.provider.TwidereDataStore.Tabs;
 
-/**
- * Created by mariotaku on 16/3/6.
- */
 @ParcelablePlease(allFields = false)
 @CursorObject(valuesCreator = true, tableInfo = true)
 @JsonObject
diff --git a/twidere.component.common/src/main/java/org/mariotaku/twidere/model/tab/argument/TabArguments.java b/twidere.component.common/src/main/java/org/mariotaku/twidere/model/tab/argument/TabArguments.java
index e9f839ab2..d75417fae 100644
--- a/twidere.component.common/src/main/java/org/mariotaku/twidere/model/tab/argument/TabArguments.java
+++ b/twidere.component.common/src/main/java/org/mariotaku/twidere/model/tab/argument/TabArguments.java
@@ -34,9 +34,6 @@ import org.mariotaku.twidere.model.UserKey;
 import java.io.IOException;
 import java.util.Arrays;
 
-/**
- * Created by mariotaku on 16/3/6.
- */
 @JsonObject
 public class TabArguments implements TwidereConstants {
     @JsonField(name = "account_id")
diff --git a/twidere.component.common/src/main/java/org/mariotaku/twidere/model/tab/extra/TabExtras.java b/twidere.component.common/src/main/java/org/mariotaku/twidere/model/tab/extra/TabExtras.java
index 6b6549d0f..c2ae28e97 100644
--- a/twidere.component.common/src/main/java/org/mariotaku/twidere/model/tab/extra/TabExtras.java
+++ b/twidere.component.common/src/main/java/org/mariotaku/twidere/model/tab/extra/TabExtras.java
@@ -31,9 +31,6 @@ import org.mariotaku.twidere.annotation.CustomTabType;
 
 import java.io.IOException;
 
-/**
- * Created by mariotaku on 16/3/6.
- */
 @JsonObject
 public abstract class TabExtras implements Parcelable {
     @CallSuper
diff --git a/twidere/src/main/kotlin/org/mariotaku/ktextension/WeakProperty.kt b/twidere/src/main/kotlin/org/mariotaku/ktextension/WeakProperty.kt
index 55fa9519e..6f8336074 100644
--- a/twidere/src/main/kotlin/org/mariotaku/ktextension/WeakProperty.kt
+++ b/twidere/src/main/kotlin/org/mariotaku/ktextension/WeakProperty.kt
@@ -22,10 +22,14 @@ package org.mariotaku.ktextension
 import java.lang.ref.WeakReference
 import kotlin.reflect.KProperty
 
-class WeakDelegate<T> {
+class WeakDelegate<T>(obj: T?) {
 
     private var weakRef: WeakReference<T>? = null
 
+    init {
+        weakRef = if (obj != null) WeakReference(obj) else null
+    }
+
     operator fun getValue(thisRef: Any?, property: KProperty<*>): T? {
         return weakRef?.get()
     }
@@ -35,4 +39,4 @@ class WeakDelegate<T> {
     }
 }
 
-fun <T> weak(): WeakDelegate<T> = WeakDelegate()
\ No newline at end of file
+fun <T> weak(obj: T? = null): WeakDelegate<T> = WeakDelegate(obj)
\ No newline at end of file
diff --git a/twidere/src/main/kotlin/org/mariotaku/twidere/activity/ComposeActivity.kt b/twidere/src/main/kotlin/org/mariotaku/twidere/activity/ComposeActivity.kt
index 36977f7dc..ad39dce2b 100644
--- a/twidere/src/main/kotlin/org/mariotaku/twidere/activity/ComposeActivity.kt
+++ b/twidere/src/main/kotlin/org/mariotaku/twidere/activity/ComposeActivity.kt
@@ -108,7 +108,6 @@ import org.mariotaku.twidere.view.ShapedImageView
 import org.mariotaku.twidere.view.helper.SimpleItemTouchHelperCallback
 import org.mariotaku.twidere.view.holder.compose.MediaPreviewViewHolder
 import java.io.IOException
-import java.lang.ref.WeakReference
 import java.text.Normalizer
 import java.util.*
 import javax.inject.Inject
@@ -1920,11 +1919,10 @@ class ComposeActivity : BaseActivity(), OnMenuItemClickListener, OnClickListener
 
     private class ComposeLocationListener(activity: ComposeActivity) : LocationListener {
 
-        private val activityRef = WeakReference(activity)
+        private val activity by weak(activity)
 
         override fun onLocationChanged(location: Location) {
-            val activity = activityRef.get() ?: return
-            activity.setRecentLocation(ParcelableLocationUtils.fromLocation(location))
+            activity?.setRecentLocation(ParcelableLocationUtils.fromLocation(location))
         }
 
         override fun onStatusChanged(provider: String, status: Int, extras: Bundle) {
diff --git a/twidere/src/main/kotlin/org/mariotaku/twidere/text/style/CustomEmojiSpan.kt b/twidere/src/main/kotlin/org/mariotaku/twidere/text/style/CustomEmojiSpan.kt
index 3960ea6dd..dcb6989c2 100644
--- a/twidere/src/main/kotlin/org/mariotaku/twidere/text/style/CustomEmojiSpan.kt
+++ b/twidere/src/main/kotlin/org/mariotaku/twidere/text/style/CustomEmojiSpan.kt
@@ -30,8 +30,8 @@ import com.bumptech.glide.RequestManager
 import com.bumptech.glide.request.animation.GlideAnimation
 import com.bumptech.glide.request.target.BaseTarget
 import com.bumptech.glide.request.target.SizeReadyCallback
+import org.mariotaku.ktextension.weak
 import org.mariotaku.twidere.R
-import java.lang.ref.WeakReference
 
 class CustomEmojiSpan(
         val uri: String,
@@ -79,14 +79,7 @@ class CustomEmojiSpan(
             val textSize: Int
     ) : BaseTarget<Bitmap>() {
 
-        var drawable: Drawable?
-            get() = drawableRef?.get()
-            private set(value) {
-                drawableRef = if (value != null) WeakReference(value) else null
-                textView.invalidate()
-            }
-
-        private var drawableRef: WeakReference<Drawable>? = null
+        var drawable: Drawable? by weak()
 
         override fun onResourceReady(resource: Bitmap, glideAnimation: GlideAnimation<in Bitmap>) {
             drawable = BitmapDrawable(textView.resources, resource)