Add long press toast for FAB

src/main/scala/com/github/shadowsocks/Shadowsocks.scala

@@ -505,6 +505,11 @@ class Shadowsocks
           }
       }
     })
+    fab.setOnLongClickListener((v: View) => {
+      Utils.positionToast(Toast.makeText(this, if (serviceStarted) R.string.stop else R.string.connect,
+        Toast.LENGTH_SHORT), fab, getWindow, 0, Utils.dpToPx(this, 8).toInt).show
+      true
+    })
     toolbar.setNavigationIcon(R.drawable.ic_drawer)
     toolbar.setNavigationOnClickListener((v: View) => drawer.toggleMenu())
     title.setOnLongClickListener((v: View) => {

src/main/scala/com/github/shadowsocks/utils/Utils.scala

@@ -50,7 +50,10 @@ import android.graphics.drawable.{BitmapDrawable, Drawable}
 import android.os.Build
 import android.provider.Settings
 import android.support.v4.content.ContextCompat
-import android.util.{Base64, Log}
+import android.util.{DisplayMetrics, Base64, Log}
+import android.view.View.MeasureSpec
+import android.view.{Gravity, View, Window}
+import android.widget.Toast
 import com.github.shadowsocks.BuildConfig
 import org.xbill.DNS._
 
@@ -126,6 +129,23 @@ object Utils {
     bitmap
   }
 
+  // Based on: http://stackoverflow.com/a/21026866/2245107
+  def positionToast(toast: Toast, view: View, window: Window, offsetX: Int = 0, offsetY: Int = 0) = {
+    val rect = new Rect
+    window.getDecorView.getWindowVisibleDisplayFrame(rect)
+    val viewLocation = new Array[Int](2)
+    view.getLocationInWindow(viewLocation)
+    val metrics = new DisplayMetrics
+    window.getWindowManager.getDefaultDisplay.getMetrics(metrics)
+    val toastView = toast.getView
+    toastView.measure(MeasureSpec.makeMeasureSpec(metrics.widthPixels, MeasureSpec.UNSPECIFIED),
+      MeasureSpec.makeMeasureSpec(metrics.heightPixels, MeasureSpec.UNSPECIFIED))
+    toast.setGravity(Gravity.LEFT | Gravity.TOP,
+      viewLocation(0) - rect.left + (view.getWidth - toast.getView.getMeasuredWidth) / 2 + offsetX,
+      viewLocation(1) - rect.top + view.getHeight + offsetY)
+    toast
+  }
+
   // Blocked > 3 seconds
   def toggleAirplaneMode(context: Context) {
     if (Build.VERSION.SDK_INT >= 17) {