[ui] Viewer2D: display image source path

* display selectable-by-mouse source filepath
* add radius property to FloatingPane to control border radius from outside
* use FloatingPane in ImageMetadataView

meshroom/ui/qml/Controls/FloatingPane.qml

@@ -10,8 +10,9 @@ Pane {
     id: root
 
     property bool opaque: false
+    property int radius: 1
 
     padding: 6
     anchors.margins: 2
-    background: Rectangle { color: root.palette.base; opacity: opaque ? 1.0 : 0.7; radius: 1 }
+    background: Rectangle { color: root.palette.base; opacity: opaque ? 1.0 : 0.7; radius: root.radius }
 }

meshroom/ui/qml/Viewer/ImageMetadataView.qml

@@ -11,7 +11,7 @@ import Utils 1.0
 /**
  * ImageMetadataView displays a JSON model representing an image"s metadata as a ListView.
  */
-Pane {
+FloatingPane {
     id: root
 
     property alias metadata: metadataModel.metadata
@@ -22,8 +22,6 @@ Pane {
 
     SystemPalette { id: palette }
 
-    background: Rectangle { color: palette.window; opacity: 0.9 }
-
     /**
      * Convert GPS metadata to degree coordinates.
      *

meshroom/ui/qml/Viewer/Viewer2D.qml

@@ -2,7 +2,8 @@ import QtQuick 2.7
 import QtQuick.Controls 2.0
 import QtQuick.Layouts 1.3
 import MaterialIcons 2.2
-import Utils 1.0
+
+import Controls 1.0
 
 FocusScope {
     id: root
@@ -115,14 +116,30 @@ FocusScope {
         }
     }
 
+    FloatingPane {
+        id: topToolbar
+        width: parent.width
+        radius: 0
+        padding: 4
+        // selectable filepath to source image
+        TextField {
+            width: parent.width
+            padding: 0
+            background: Item {}
+            font.pointSize: 8
+            readOnly: true
+            selectByMouse: true
+            text: Filepath.urlToString(source)
+        }
+    }
+
     // Image Metadata overlay Pane
     ImageMetadataView {
         width: 350
         anchors {
-            top: parent.top
+            top: topToolbar.bottom
             right: parent.right
             bottom: bottomToolbar.top
-            margins: 2
         }
 
         visible: metadataCB.checked
@@ -130,15 +147,13 @@ FocusScope {
         metadata: visible ? root.metadata : {}
     }
 
-    Pane {
+    FloatingPane {
         id: bottomToolbar
         anchors.bottom: parent.bottom
+        anchors.margins: 0
         width: parent.width
-        padding: 2
-        leftPadding: 4
-        rightPadding: leftPadding
-
-        background: Rectangle { color: palette.base; opacity: 0.6 }
+        topPadding: 2
+        bottomPadding: topPadding
 
         RowLayout {
             anchors.fill: parent