Add share button to the Session Detail Screen

app/src/main/java/io/github/droidkaigi/confsched2018/presentation/detail/SessionDetailFragment.kt

@@ -2,6 +2,7 @@ package io.github.droidkaigi.confsched2018.presentation.detail
 
 import android.arch.lifecycle.ViewModelProvider
 import android.arch.lifecycle.ViewModelProviders
+import android.content.Intent
 import android.graphics.drawable.Animatable
 import android.os.Bundle
 import android.support.v4.app.Fragment
@@ -84,6 +85,15 @@ class SessionDetailFragment : Fragment(), Injectable {
             sessionDetailViewModel.onFavoriteClick(session)
             sessionAlarm.toggleRegister(session)
         }
+        binding.shareButton.setOnClickListener {
+            val shareIntent = Intent(Intent.ACTION_SEND).apply {
+                type = resources.getString(R.string.session_share_intent_type)
+                val text = generateSharedText(session)
+                putExtra(Intent.EXTRA_TEXT, text)
+            }
+            startActivity(Intent.createChooser(shareIntent,
+                    resources.getString(R.string.session_share_via)))
+        }
         binding.sessionTopic.text = session.topic.getNameByLang(lang())
         val levelDrawable = binding.context.drawable(when (session.level) {
             is Level.Beginner -> R.drawable.ic_beginner_lightgreen_20dp
@@ -98,6 +108,40 @@ class SessionDetailFragment : Fragment(), Injectable {
         }
     }
 
+    /**
+     * Generate a shared text
+     *
+     * e.g.
+     * ConstraintLayout, now and future (Nicolas Roard, John Hoford, thagikura) #droidkaigi_room6
+     * https://droidkaigi.jp/2018/timetable/?session=16988
+     *
+     * @param session The [Session.SpeechSession] object
+     * @return A shared text
+     */
+    private fun generateSharedText(session: Session.SpeechSession): String {
+        val speakers = session.speakers.joinToString(", ") { it.name }
+        val hashTag = generateHashTagByRoom(session.room.name)
+        val title = resources.getString(R.string.session_share_title,
+                session.title,
+                speakers,
+                hashTag)
+        val url = resources.getString(R.string.session_share_url, session.id)
+        return "$title\n$url"
+    }
+
+    /**
+     * Generate a hash tag by room name.
+     *
+     * e.g. #droidkaigi_hall, #droidkaigi_room1, ...
+     *
+     * @param roomName The Room name
+     * @return A hash tag
+     */
+    private fun generateHashTagByRoom(roomName: String): String {
+        val lowerCasedName = roomName.replace(" ", "").toLowerCase()
+        return resources.getString(R.string.session_share_hash_tag, lowerCasedName)
+    }
+
     private fun updateDrawable() {
         val img = if (binding.fab.isActivated) R.drawable.ic_anim_favorite_unchecking else R.drawable.ic_anim_favorite_checking
         binding.fab.setImageResource(img)

app/src/main/res/drawable/ic_share_white_24dp.xml

@@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+        android:width="24dp"
+        android:height="24dp"
+        android:viewportWidth="24.0"
+        android:viewportHeight="24.0">
+    <path
+        android:fillColor="#FFFFFFFF"
+        android:pathData="M18,16.08c-0.76,0 -1.44,0.3 -1.96,0.77L8.91,12.7c0.05,-0.23 0.09,-0.46 0.09,-0.7s-0.04,-0.47 -0.09,-0.7l7.05,-4.11c0.54,0.5 1.25,0.81 2.04,0.81 1.66,0 3,-1.34 3,-3s-1.34,-3 -3,-3 -3,1.34 -3,3c0,0.24 0.04,0.47 0.09,0.7L8.04,9.81C7.5,9.31 6.79,9 6,9c-1.66,0 -3,1.34 -3,3s1.34,3 3,3c0.79,0 1.5,-0.31 2.04,-0.81l7.12,4.16c-0.05,0.21 -0.08,0.43 -0.08,0.65 0,1.61 1.31,2.92 2.92,2.92 1.61,0 2.92,-1.31 2.92,-2.92s-1.31,-2.92 -2.92,-2.92z"/>
+</vector>

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

@@ -130,6 +130,18 @@
                             app:speakers="@{session.speakers}"
                             app:textColor="@color/app_bar_text_color"
                             />
+                        <ImageView
+                            android:id="@+id/share_button"
+                            android:layout_width="wrap_content"
+                            android:layout_height="wrap_content"
+                            android:layout_marginEnd="16dp"
+                            android:background="?attr/selectableItemBackground"
+                            android:contentDescription="@string/session_content_description_share"
+                            android:padding="8dp"
+                            app:layout_constraintEnd_toEndOf="parent"
+                            app:layout_constraintTop_toTopOf="@+id/session_title"
+                            app:srcCompat="@drawable/ic_share_white_24dp"
+                            />
 
                     </android.support.constraint.ConstraintLayout>
 

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

@@ -29,6 +29,7 @@
     <string name="session_load_retry">リトライ</string>
     <string name="session_finished">終了済みのセッション</string>
     <string name="session_go_to_feedback">アンケートへ</string>
+    <string name="session_share_via">シェア</string>
 
     <!-- Session detail -->
     <string name="detail_sessions_next">Next</string>

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

@@ -37,6 +37,12 @@
     <string name="session_finished">Finished Session</string>
     <string name="session_go_to_feedback">Go To Feedback</string>
     <string name="session_current_badge" translatable="false">NOW!</string>
+    <string name="session_share_url" translatable="false">https://droidkaigi.jp/2018/timetable?session=%s</string>
+    <string name="session_share_title" translatable="false">%1$s (%2$s) %3$s</string>
+    <string name="session_share_hash_tag" translatable="false">#droidkaigi_%s</string>
+    <string name="session_share_intent_type" translatable="false">text/plain</string>
+    <string name="session_share_via">Share via</string>
+    <string name="session_content_description_share">Share button</string>
 
     <!-- Session detail -->
     <string name="detail_sessions_next">Next</string>