Kotlinize the playground demo app (#329)

Kotlinize the playground demo app

Author: thagikura

demo-playground/build.gradle

@@ -15,6 +15,7 @@
  */
 
 apply plugin: 'com.android.application'
+apply plugin: 'kotlin-android'
 
 android {
     compileSdkVersion rootProject.ext.compileSdkVersion
@@ -45,6 +46,7 @@ dependencies {
     compile "com.android.support:preference-v7:${rootProject.ext.supportLibVersion}"
     compile "com.android.support:preference-v14:${rootProject.ext.supportLibVersion}"
     compile "com.android.support:design:${rootProject.ext.supportLibVersion}"
+    compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlinVersion"
 
     testCompile "junit:junit:${rootProject.ext.junitVersion}"
 

demo-playground/src/main/java/com/google/android/flexbox/Extensions.kt

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2017 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.android.flexbox
+
+import android.content.Context
+
+/**
+ * Convert pixel to dp. Preserve the negative value as it's used for representing
+ * MATCH_PARENT(-1) and WRAP_CONTENT(-2).
+ * Ignore the round error that might happen in dividing the pixel by the density.
+ *
+ * @param pixel   the value in pixel
+ *
+ * @return the converted value in dp
+ */
+fun Context.pixelToDp(pixel: Int): Int {
+    val displayMetrics = this.resources.displayMetrics
+    return if (pixel < 0) pixel else Math.round(pixel / displayMetrics.density)
+}
+
+/**
+ * Convert dp to pixel. Preserve the negative value as it's used for representing
+ * MATCH_PARENT(-1) and WRAP_CONTENT(-2).
+ *
+ * @param dp      the value in dp
+ *
+ * @return the converted value in pixel
+ */
+fun Context.dpToPixel(dp: Int): Int {
+    val displayMetrics = this.resources.displayMetrics
+    return if (dp < 0) dp else Math.round(dp * displayMetrics.density)
+}

demo-playground/src/main/java/com/google/android/flexbox/FlexItemAdapter.kt

@@ -0,0 +1,65 @@
+/*
+ * Copyright 2017 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.android.flexbox
+
+import android.support.v7.app.AppCompatActivity
+import android.support.v7.widget.RecyclerView
+import android.view.LayoutInflater
+import android.view.ViewGroup
+import com.google.android.apps.flexbox.R
+
+/**
+ * [RecyclerView.Adapter] implementation for [FlexItemViewHolder].
+ */
+internal class FlexItemAdapter(private val activity: AppCompatActivity, private val flexContainer: FlexContainer) : RecyclerView.Adapter<FlexItemViewHolder>() {
+
+    private val layoutParams = mutableListOf<FlexboxLayoutManager.LayoutParams>()
+
+    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): FlexItemViewHolder {
+        val view = LayoutInflater.from(parent.context)
+                .inflate(R.layout.viewholder_flex_item, parent, false)
+
+        return FlexItemViewHolder(view)
+    }
+
+    override fun onBindViewHolder(holder: FlexItemViewHolder, position: Int) {
+        val adapterPosition = holder.adapterPosition
+        // TODO: More optimized set the click listener inside the view holder
+        holder.itemView.setOnClickListener(FlexItemClickListener(activity,
+                FlexItemChangedListenerImplRecyclerView(flexContainer, this),
+                adapterPosition))
+        holder.bindTo(layoutParams[position])
+    }
+
+    fun addItem(lp: FlexboxLayoutManager.LayoutParams) {
+        layoutParams.add(lp)
+        notifyItemInserted(layoutParams.size - 1)
+    }
+
+    fun removeItem(position: Int) {
+        if (position < 0 || position >= layoutParams.size) {
+            return
+        }
+        layoutParams.removeAt(position)
+        notifyItemRemoved(layoutParams.size)
+        notifyItemRangeChanged(position, layoutParams.size)
+    }
+
+    val items get() = layoutParams
+
+    override fun getItemCount() = layoutParams.size
+}

…oid/flexbox/FlexItemChangedListener.java …droid/flexbox/FlexItemChangedListener.ktdemo-playground/src/main/java/com/google/android/flexbox/FlexItemChangedListener.java renamed to demo-playground/src/main/java/com/google/android/flexbox/FlexItemChangedListener.kt demo-playground/src/main/java/com/google/android/flexbox/FlexItemChangedListener.java renamed to demo-playground/src/main/java/com/google/android/flexbox/FlexItemChangedListener.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 Google Inc. All rights reserved.
+ * Copyright 2017 Google Inc. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,12 +14,12 @@
  * limitations under the License.
  */
 
-package com.google.android.flexbox;
+package com.google.android.flexbox
 
 /**
  * A listener that listens to the change of a flex item
  */
-public interface FlexItemChangedListener {
+internal interface FlexItemChangedListener {
 
-    void onFlexItemChanged(FlexItem flexItem, int viewIndex);
+    fun onFlexItemChanged(flexItem: FlexItem, viewIndex: Int)
 }

demo-playground/src/main/java/com/google/android/flexbox/FlexItemChangedListenerImpl.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2017 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.android.flexbox
+
+import android.view.ViewGroup
+
+/**
+ * Default implementation for the [FlexItemChangedListener].
+ */
+internal class FlexItemChangedListenerImpl(private val flexContainer: FlexContainer) : FlexItemChangedListener {
+
+    override fun onFlexItemChanged(flexItem: FlexItem, viewIndex: Int) {
+        val view = flexContainer.getFlexItemAt(viewIndex)
+        view.layoutParams = flexItem as ViewGroup.LayoutParams
+    }
+}

demo-playground/src/main/java/com/google/android/flexbox/FlexItemChangedListenerImpl.kt

@@ -14,33 +14,22 @@
  * limitations under the License.
  */
 
-package com.google.android.flexbox;
+package com.google.android.flexbox
 
-import android.support.v7.widget.RecyclerView;
-import android.view.View;
-import android.view.ViewGroup;
+import android.support.v7.widget.RecyclerView
+import android.view.ViewGroup
 
 /**
- * Implementation for the {@link FlexItemChangedListener}.
+ * Implementation for the [FlexItemChangedListener].
  * It expects RecyclerView as the underlying flex container implementation.
  */
-public class FlexItemChangedListenerImplRecyclerView implements FlexItemChangedListener {
+internal class FlexItemChangedListenerImplRecyclerView(private val flexContainer: FlexContainer,
+                                              private val adapter: RecyclerView.Adapter<*>) : FlexItemChangedListener {
 
-    private FlexContainer mFlexContainer;
-
-    private RecyclerView.Adapter mAdapter;
-
-    public FlexItemChangedListenerImplRecyclerView(FlexContainer flexContainer,
-            RecyclerView.Adapter adapter) {
-        mFlexContainer = flexContainer;
-        mAdapter = adapter;
-    }
-
-    @Override
-    public void onFlexItemChanged(FlexItem flexItem, int viewIndex) {
-        View view = mFlexContainer.getFlexItemAt(viewIndex);
-        view.setLayoutParams((ViewGroup.LayoutParams) flexItem);
-        mAdapter.notifyDataSetChanged();
+    override fun onFlexItemChanged(flexItem: FlexItem, viewIndex: Int) {
+        val view = flexContainer.getFlexItemAt(viewIndex)
+        view.layoutParams = flexItem as ViewGroup.LayoutParams
+        adapter.notifyDataSetChanged()
         // TODO: An Exception is thrown if notifyItemChanged(int) is used.
         // Investigate that, but using LinearLayoutManager also produces the same Exception
         // java.lang.IllegalArgumentException: Called attach on a child which is not detached:

…ItemChangedListenerImplRecyclerView.java …exItemChangedListenerImplRecyclerView.ktdemo-playground/src/main/java/com/google/android/flexbox/FlexItemChangedListenerImplRecyclerView.java renamed to demo-playground/src/main/java/com/google/android/flexbox/FlexItemChangedListenerImplRecyclerView.kt demo-playground/src/main/java/com/google/android/flexbox/FlexItemChangedListenerImplRecyclerView.java renamed to demo-playground/src/main/java/com/google/android/flexbox/FlexItemChangedListenerImplRecyclerView.kt

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2017 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.android.flexbox
+
+import android.support.v7.app.AppCompatActivity
+import android.view.View
+
+/**
+ * Implementation of the [android.view.View.OnClickListener] when a flex item is clicked in
+ * the Flexbox Playground demo app.
+ */
+internal class FlexItemClickListener(private val activity: AppCompatActivity, private val flexItemChangedListener: FlexItemChangedListener,
+                                     private val viewIndex: Int) : View.OnClickListener {
+
+    override fun onClick(v: View) {
+        val fragment = FlexItemEditFragment
+                .newInstance(v.layoutParams as FlexItem, viewIndex)
+        fragment.setFlexItemChangedListener(flexItemChangedListener)
+        fragment.show(activity.supportFragmentManager, EDIT_DIALOG_TAG)
+    }
+
+    companion object {
+
+        private const val EDIT_DIALOG_TAG = "edit_dialog_tag"
+    }
+}