Smart grid (#56)

* Refactor classes to a more package-by-feature approach

* Fix a potential NPE

* Auto-fit grid. Fixes #45. Fixes #46.

* Fixes a visual issue

app/src/main/kotlin/app/gaming/AutoFitStaggeredGridRecyclerView.kt

@@ -0,0 +1,43 @@
+package app.gaming
+
+import android.content.Context
+import android.support.annotation.Px
+import android.support.v7.widget.RecyclerView
+import android.support.v7.widget.StaggeredGridLayoutManager
+import android.util.AttributeSet
+import org.jorge.ms.app.R
+import util.android.ext.getDimension
+
+/**
+ * A recycler view that automatically attaches to itself a GridLayoutManager and performs auto-fit
+ * with its elements.
+ * @param context The context
+ * @param attrs The attributes
+ * @see <a href="http://blog.sqisland.com/2014/12/recyclerview-autofit-grid.html">
+ *     Square Island: RecyclerView: Autofit grid</a>
+ */
+internal class AutoFitStaggeredGridRecyclerView(context: Context, attrs: AttributeSet?)
+    : RecyclerView(context, attrs) {
+    private @Px val columnWidth: Int
+
+    init {
+        @Px val defaultColumnWidth = context.getDimension(R.dimen.default_column_width).toInt()
+        if (attrs != null) {
+            val attrsArray = intArrayOf(android.R.attr.columnWidth)
+            val typedArray = context.obtainStyledAttributes(attrs, attrsArray)
+            columnWidth = typedArray.getDimensionPixelSize(0, defaultColumnWidth)
+            typedArray.recycle()
+        } else {
+            columnWidth = defaultColumnWidth
+        }
+        layoutManager = StaggeredGridLayoutManager(1, StaggeredGridLayoutManager.VERTICAL)
+    }
+
+    override fun onMeasure(widthSpec: Int, heightSpec: Int) {
+        super.onMeasure(widthSpec, heightSpec)
+        if (columnWidth > 0) {
+            val spanCount = Math.max(1, measuredWidth / columnWidth)
+            (layoutManager as StaggeredGridLayoutManager).spanCount = spanCount
+        }
+    }
+}

app/src/main/kotlin/app/widget/CompatRippleLinearLayout.kt → app/src/main/kotlin/app/gaming/CompatRippleLinearLayout.kt

@@ -1,4 +1,4 @@
-package app.widget
+package app.gaming
 
 import android.content.Context
 import android.graphics.Canvas
@@ -9,15 +9,15 @@ import android.view.MotionEvent
 import android.view.animation.Animation
 import android.view.animation.Transformation
 import android.widget.LinearLayout
+import org.jorge.ms.app.R
 import util.android.ext.getColorCompat
 import util.android.ext.getInteger
-import org.jorge.ms.app.R
 
 /**
  * @see <a href="https://androidreclib.wordpress.com/2014/11/18/the-touch-ripple-on-gingerbread/">
  *     The touch ripple on Gingerbread | Android Rec Library</>
  */
-internal class CompatRippleLinearLayout(context: Context, attrs: AttributeSet)
+internal class CompatRippleLinearLayout(context: Context, attrs: AttributeSet?)
     : LinearLayout(context, attrs) {
     private val rippleColor = context.getColorCompat(R.color.default_ripple)
     private val rippleDuration = context.getInteger(android.R.integer.config_shortAnimTime).toLong()

app/src/main/kotlin/app/widget/LoadableContentView.kt → app/src/main/kotlin/app/gaming/LoadableContentView.kt

@@ -1,4 +1,4 @@
-package app.widget
+package app.gaming
 
 /**
  * An interface describing the behavior required by views bound to coordinators.

app/src/main/kotlin/app/gaming/TopGamingAllTimePostsContentViewConfig.kt

@@ -1,6 +1,5 @@
 package app.gaming
 
-import android.content.Context
 import android.support.v7.widget.LinearLayoutManager
 import android.support.v7.widget.RecyclerView
 import android.support.v7.widget.StaggeredGridLayoutManager
@@ -12,7 +11,6 @@ import android.widget.TextView
 import domain.entity.Post
 import org.jorge.ms.app.R
 import util.android.ext.getDimension
-import util.android.ext.isPortrait
 
 /**
  * Configures the recycler view holding the post list.
@@ -25,7 +23,6 @@ internal object TopGamingAllTimePostsContentViewConfig {
     internal fun dumpOnto(view: TopGamingAllTimePostsView, callback: TopGamingAllTimePostsActivity.BehaviorCallback) {
         view.contentView.let { recyclerView ->
             recyclerView.adapter = provideAdapter(callback)
-            recyclerView.layoutManager = provideLayoutManager(recyclerView.context)
             recyclerView.addOnScrollListener(provideEndlessLoadListener(
                     recyclerView.layoutManager, callback))
             recyclerView.setHasFixedSize(false)
@@ -48,27 +45,14 @@ internal object TopGamingAllTimePostsContentViewConfig {
         return adapter
     }
 
-    /**
-     * Provides a layout manager based on the size of the screen.
-     * @param context The context
-     */
-    private fun provideLayoutManager(context: Context): RecyclerView.LayoutManager
-        = if (context.isPortrait()) {
-            LinearLayoutManager(context)
-        } else {
-            val ret = StaggeredGridLayoutManager(3, StaggeredGridLayoutManager.VERTICAL)
-            ret.gapStrategy = StaggeredGridLayoutManager.GAP_HANDLING_MOVE_ITEMS_BETWEEN_SPANS
-            ret
-        }
-    }
-
     private fun provideEndlessLoadListener(layoutManager: RecyclerView.LayoutManager,
                                            callback: TopGamingAllTimePostsActivity.BehaviorCallback)
             = object : EndlessLoadListener(layoutManager) {
         override fun onLoadMore() {
             callback.onPageLoadRequested()
         }
     }
+}
 
 /**
  * A very simple adapter backed by a mutable list that exposes a method to add items.

app/src/main/kotlin/app/gaming/TopGamingAllTimePostsCoordinator.kt

@@ -2,7 +2,7 @@ package app.gaming
 
 import android.support.annotation.VisibleForTesting
 import app.UIPostExecutionThread
-import app.widget.LoadableContentView
+import app.gaming.LoadableContentView
 import com.google.firebase.crash.FirebaseCrash
 import domain.entity.Post
 import domain.interactor.TopGamingAllTimeFetchPostsUseCase

app/src/main/kotlin/app/gaming/TopGamingAllTimePostsView.kt

@@ -2,7 +2,7 @@ package app.gaming
 
 import android.support.v7.widget.RecyclerView
 import android.view.View
-import app.widget.LoadableContentView
+import app.gaming.LoadableContentView
 import domain.entity.Post
 
 /**

app/src/main/res/layout/include_top_posts_view.xml

@@ -3,11 +3,12 @@
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="wrap_content">
-    <android.support.v7.widget.RecyclerView
+    <app.gaming.AutoFitStaggeredGridRecyclerView
         android:id="@+id/content"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
-        android:overScrollMode="never" />
+        android:overScrollMode="never"
+        android:columnWidth="@dimen/top_posts_column_width" />
     <android.support.v4.widget.ContentLoadingProgressBar
         android:id="@+id/progress"
         android:layout_width="match_parent"

app/src/main/res/layout/item_post.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<app.widget.CompatRippleLinearLayout
+<app.gaming.CompatRippleLinearLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
@@ -40,4 +40,4 @@
             android:textIsSelectable="false"
             style="@style/AppTheme.TextSubhead" />
     </LinearLayout>
-</app.widget.CompatRippleLinearLayout>
+</app.gaming.CompatRippleLinearLayout>

app/src/main/res/values/dimens.xml

@@ -6,4 +6,6 @@
     <dimen name="item_separation">16dp</dimen>
     <dimen name="section_separator">16dp</dimen>
     <dimen name="text_separation">12dp</dimen>
+    <dimen name="default_column_width">150dp</dimen>
+    <dimen name="top_posts_column_width">200dp</dimen>
 </resources>

app/src/main/res/values/strings.xml

@@ -3,5 +3,5 @@
     <string name="app_label">reddit</string>
     <string name="top_posts_error_description">Finished loading</string>
     <string name="top_posts_error_action">Retry</string>
-    <string name="subreddit_template">/r/%s</string>
+    <string name="subreddit_template">r/%s</string>
 </resources>

util-android/src/main/kotlin/util/android/ext/Context.kt

@@ -7,13 +7,13 @@ import android.support.annotation.DimenRes
 import android.support.annotation.IntegerRes
 
 /**
- * Extension function to reduce verbosity to getInteger(...).
+ * Extension function to reduce verbosity to resources.getInteger(...).
  * @param resId The id of the resource to get.
  */
 fun Context.getInteger(@IntegerRes resId: Int) = this.resources.getInteger(resId)
 
 /**
- * Extension function to reduce verbosity to getColor(...).
+ * Extension function to reduce verbosity to resources.getColor(...).
  * @param resId The id of the resource to get.
  */
 fun Context.getColorCompat(@ColorRes resId: Int) =
@@ -24,14 +24,7 @@ fun Context.getColorCompat(@ColorRes resId: Int) =
             this.resources.getColor(resId)
 
 /**
- * Extension function to reduce verbosity to getDimension(...).
+ * Extension function to reduce verbosity to resources.getDimension(...).
  * @param resId The id of the resource to get.
  */
 fun Context.getDimension(@DimenRes resId: Int) = this.resources.getDimension(resId)
-
-/**
- * Extension function to check if the device is in portrait mode.
- */
-fun Context.isPortrait() = this.resources.displayMetrics.let {
-    it.heightPixels > it.widthPixels
-}