1 files changed, 98 insertions, 0 deletions
diff --git a/app/src/main/kotlin/com/pitchedapps/frost/utils/Changelog.kt b/app/src/main/kotlin/com/pitchedapps/frost/utils/Changelog.kt
new file mode 100644
index 00000000..14a095a1
--- /dev/null
+++ b/app/src/main/kotlin/com/pitchedapps/frost/utils/Changelog.kt
@@ -0,0 +1,98 @@
+package com.pitchedapps.frost.utils
+
+import android.content.Context
+import android.content.res.XmlResourceParser
+import android.os.Handler
+import android.support.annotation.LayoutRes
+import android.support.annotation.NonNull
+import android.support.annotation.XmlRes
+import android.support.v4.app.FragmentActivity
+import android.support.v7.widget.RecyclerView
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.widget.TextView
+import com.afollestad.materialdialogs.MaterialDialog
+import com.pitchedapps.frost.R
+import org.xmlpull.v1.XmlPullParser
+import java.util.*
+
+
+/**
+ * Created by Allan Wang on 2017-05-28.
+ */
+class Changelog {
+    companion object {
+        fun show(@NonNull activity: FragmentActivity, @XmlRes xmlRes: Int = R.xml.changelog) {
+            val mHandler = Handler()
+            Thread(Runnable {
+                val items = parse(activity, xmlRes)
+                mHandler.post(object : TimerTask() {
+                    override fun run() {
+                        MaterialDialog.Builder(activity)
+                                .title(R.string.changelog)
+                                .positiveText(R.string.great)
+                                .adapter(ChangelogAdapter(items), null)
+                                .show()
+                    }
+                })
+            }).start()
+        }
+    }
+}
+
+private class ChangelogAdapter(val items: List<Pair<String, ChangelogType>>) : RecyclerView.Adapter<ChangelogAdapter.ChangelogVH>() {
+
+    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int) = ChangelogVH(LayoutInflater.from(parent.context)
+            .inflate(getLayout(viewType), parent, false))
+
+    private fun getLayout(position: Int) = items[position].second.layout
+
+    override fun onBindViewHolder(holder: ChangelogVH, position: Int) {
+        holder.text.text = items[position].first
+    }
+
+    override fun getItemId(position: Int) = position.toLong()
+
+    override fun getItemViewType(position: Int) = position
+
+    override fun getItemCount() = items.size
+
+    internal class ChangelogVH(itemView: View) : RecyclerView.ViewHolder(itemView) {
+        val text: TextView = itemView.findViewById(R.id.changelog_text) as TextView
+    }
+}
+
+private fun parse(context: Context, @XmlRes xmlRes: Int): List<Pair<String, ChangelogType>> {
+    val items = mutableListOf<Pair<String, ChangelogType>>()
+    context.resources.getXml(xmlRes).use {
+        parser ->
+        var eventType = parser.eventType
+        while (eventType != XmlPullParser.END_DOCUMENT) {
+            if (eventType == XmlPullParser.START_TAG)
+                ChangelogType.values.any { it.add(parser, items) }
+            eventType = parser.next()
+        }
+    }
+    return items
+}
+
+private enum class ChangelogType(val tag: String, val attr: String, @LayoutRes val layout: Int) {
+    TITLE("title", "version", R.layout.changelog_title),
+    ITEM("item", "text", R.layout.changelog_content);
+
+    companion object {
+        val values = values()
+    }
+
+    /**
+     * Returns true if tag matches; false otherwise
+     */
+    fun add(parser: XmlResourceParser, list: MutableList<Pair<String, ChangelogType>>): Boolean {
+        if (parser.name != tag) return false
+        if (parser.getAttributeValue(null, attr).isNotBlank())
+            list.add(Pair(parser.getAttributeValue(null, attr), this))
+        return true
+    }
+}
+