wasm: enable mobile native keyboarding

This works on iOS and Android, and Windows with touchscreen.

On Android, we need to listen to the input event
of a hidden text element and synthesize Qt keyboard
events from that in order to get input events into Qt.

On Windows, we need to be more creative about bringing the native
virtual keyboard up.

Because the entire canvas is contenteditable, we need to specify the
inputmode is set to 'none', otherwise the v keyboard pops up
when user clicks anywhere on the canvas. Therefore we set a hidden
element as contenteditable, which pops up keyboard when Qt
needs it for editable widgets. On Android, this is the same
element that is used to proxy the keyboard input.

[ChangeLog][wasm] Add support for native mobile keyboard

Done-with: Morten Johan Sørvig <morten.sorvig@qt.io>
Fixes: QTBUG-83064
Fixes: QTBUG-88803
Change-Id: I769fe344fc10c17971bd1c0a603501040fe82653
Reviewed-by: David Skoland <david.skoland@qt.io>
Reviewed-by: Morten Johan Sørvig <morten.sorvig@qt.io>

1 files changed, 23 insertions, 0 deletions

diff --git a/src/plugins/platforms/wasm/qwasmintegration.cpp b/src/plugins/platforms/wasm/qwasmintegration.cpp
index 031128563e..01fb9f1cd0 100644
--- a/src/plugins/platforms/wasm/qwasmintegration.cpp
+++ b/src/plugins/platforms/wasm/qwasmintegration.cpp
@@ -106,6 +106,22 @@ QWasmIntegration::QWasmIntegration()
 {
     s_instance = this;
 
+   touchPoints = emscripten::val::global("navigator")["maxTouchPoints"].as<int>();
+    // The Platform Detect: expand coverage as needed
+    platform = GenericPlatform;
+    emscripten::val rawPlatform = emscripten::val::global("navigator")["platform"];
+
+    if (rawPlatform.call<bool>("includes", emscripten::val("Mac")))
+        platform = MacOSPlatform;
+    if (rawPlatform.call<bool>("includes", emscripten::val("Win32")))
+        platform = WindowsPlatform;
+    if (rawPlatform.call<bool>("includes", emscripten::val("Linux"))) {
+        platform = LinuxPlatform;
+        emscripten::val uAgent = emscripten::val::global("navigator")["userAgent"];
+        if (uAgent.call<bool>("includes", emscripten::val("Android")))
+            platform = AndroidPlatform;
+    }
+
     // We expect that qtloader.js has populated Module.qtCanvasElements with one or more canvases.
     emscripten::val qtCanvaseElements = val::module_property("qtCanvasElements");
     emscripten::val canvas = val::module_property("canvas"); // TODO: remove for Qt 6.0
@@ -156,6 +172,8 @@ QWasmIntegration::~QWasmIntegration()
 
     delete m_fontDb;
     delete m_desktopServices;
+    if (m_platformInputContext)
+        delete m_platformInputContext;
 
     for (const auto &canvasAndScreen : m_screens)
         QWindowSystemInterface::handleScreenRemoved(canvasAndScreen.second);
@@ -210,9 +228,14 @@ QPlatformOpenGLContext *QWasmIntegration::createPlatformOpenGLContext(QOpenGLCon
 
 void QWasmIntegration::initialize()
 {
+    if (touchPoints < 1) // only touchscreen need inputcontexts
+        return;
+
     QString icStr = QPlatformInputContextFactory::requested();
     if (!icStr.isNull())
         m_inputContext.reset(QPlatformInputContextFactory::create(icStr));
+    else
+        m_inputContext.reset(new QWasmInputContext());
 }
 
 QPlatformInputContext *QWasmIntegration::inputContext() const