Merge pull request #325 from pangeachat/toolbar-stay-onscreen

Toolbar stay onscreen

lib/pangea/widgets/chat/message_toolbar.dart

@@ -59,6 +59,7 @@ class ToolbarDisplayController {
   }
 
   void showToolbar(BuildContext context, {MessageMode? mode}) {
+    bool toolbarUp = true;
     if (highlighted) return;
     if (controller.selectMode) {
       controller.clearSelectedEvents();
@@ -76,8 +77,22 @@ class ToolbarDisplayController {
     if (targetRenderBox != null) {
       final Size transformTargetSize = (targetRenderBox as RenderBox).size;
       messageWidth = transformTargetSize.width;
+      final Offset targetOffset = (targetRenderBox).localToGlobal(Offset.zero);
+      final double screenHeight = MediaQuery.of(context).size.height;
+      toolbarUp = targetOffset.dy >= screenHeight / 2;
     }
 
+    final Widget overlayMessage = OverlayMessage(
+      pangeaMessageEvent.event,
+      timeline: pangeaMessageEvent.timeline,
+      immersionMode: immersionMode,
+      ownMessage: pangeaMessageEvent.ownMessage,
+      toolbarController: this,
+      width: messageWidth,
+      nextEvent: nextEvent,
+      previousEvent: previousEvent,
+    );
+
     WidgetsBinding.instance.addPostFrameCallback((timeStamp) {
       Widget overlayEntry;
       if (toolbar == null) return;
@@ -88,18 +103,9 @@ class ToolbarDisplayController {
               ? CrossAxisAlignment.end
               : CrossAxisAlignment.start,
           children: [
-            toolbar!,
+            toolbarUp ? toolbar! : overlayMessage,
             const SizedBox(height: 6),
-            OverlayMessage(
-              pangeaMessageEvent.event,
-              timeline: pangeaMessageEvent.timeline,
-              immersionMode: immersionMode,
-              ownMessage: pangeaMessageEvent.ownMessage,
-              toolbarController: this,
-              width: messageWidth,
-              nextEvent: nextEvent,
-              previousEvent: previousEvent,
-            ),
+            toolbarUp ? overlayMessage : toolbar!,
           ],
         );
       } catch (err) {
@@ -113,11 +119,19 @@ class ToolbarDisplayController {
         child: overlayEntry,
         transformTargetId: targetId,
         targetAnchor: pangeaMessageEvent.ownMessage
-            ? Alignment.bottomRight
-            : Alignment.bottomLeft,
+            ? toolbarUp
+                ? Alignment.bottomRight
+                : Alignment.topRight
+            : toolbarUp
+                ? Alignment.bottomLeft
+                : Alignment.topLeft,
         followerAnchor: pangeaMessageEvent.ownMessage
-            ? Alignment.bottomRight
-            : Alignment.bottomLeft,
+            ? toolbarUp
+                ? Alignment.bottomRight
+                : Alignment.topRight
+            : toolbarUp
+                ? Alignment.bottomLeft
+                : Alignment.topLeft,
         backgroundColor: const Color.fromRGBO(0, 0, 0, 1).withAlpha(100),
       );