wasm: support adding and removing canvases at runtime

Add qtloader API:
  addCanvasElement()
  removeCanvasElement()

These functions call the corresponding add/remove screen
functions on QWasmIntegration.

Task-number: QTBUG-64079
Change-Id: I537c11f3b5fb9240cca9b6313dd45f803d865ac6
Reviewed-by: Morten Johan Sørvig <morten.sorvig@qt.io>

1 files changed, 20 insertions, 0 deletions

diff --git a/src/plugins/platforms/wasm/qtloader.js b/src/plugins/platforms/wasm/qtloader.js
index 049eb1c35e..9bacce5944 100644
--- a/src/plugins/platforms/wasm/qtloader.js
+++ b/src/plugins/platforms/wasm/qtloader.js
@@ -118,6 +118,10 @@
 //      "Exited", iff crashed is false.
 // exitText
 //      Abort/exit message.
+// addCanvasElement
+//      Add canvas at run-time. Adds a corresponding QScreen,
+// removeCanvasElement
+//      Remove canvas at run-time. Removes the corresponding QScreen.
 
 
 var Module = {}
@@ -227,6 +231,8 @@ function QtLoader(config)
     publicAPI.canLoadApplication = canLoadQt();
     publicAPI.status = undefined;
     publicAPI.loadEmscriptenModule = loadEmscriptenModule;
+    publicAPI.addCanvasElement = addCanvasElement;
+    publicAPI.removeCanvasElement = removeCanvasElement;
 
     restartCount = 0;
 
@@ -528,6 +534,20 @@ function QtLoader(config)
         window.setTimeout(function() { handleStatusChange(); }, 0);
     }
 
+    function addCanvasElement(element) {
+        if (publicAPI.status == "Running")
+            Module.qtAddCanvasElement(element);
+        else
+            console.log("Error: addCanvasElement can only be called in the Running state");
+    }
+
+    function removeCanvasElement(element) {
+        if (publicAPI.status == "Running")
+            Module.qtRemoveCanvasElement(element);
+        else
+            console.log("Error: removeCanvasElement can only be called in the Running state");
+    }
+
     setStatus("Created");
 
     return publicAPI;