From 0fe900dfd23c758ff96b8ba50fdd0ae2e989c5bd Mon Sep 17 00:00:00 2001
From: falkTX <falktx@falktx.com>
Date: Thu, 9 May 2024 21:28:02 +0200
Subject: [PATCH] allow web-ui late init

Signed-off-by: falkTX <falktx@falktx.com>
---
 dgl/Web.hpp                   |  6 ++++--
 dgl/src/Web.cpp               | 34 ++++++++++++++++++++++++++--------
 distrho/extra/WebViewImpl.hpp |  7 +++++++
 distrho/src/DistrhoUI.cpp     |  8 ++++++--
 4 files changed, 43 insertions(+), 12 deletions(-)

diff --git a/dgl/Web.hpp b/dgl/Web.hpp
index 67cb3782..2a4db1ee 100644
--- a/dgl/Web.hpp
+++ b/dgl/Web.hpp
@@ -43,7 +43,7 @@ public:
    /**
       Constructor for a WebViewWidget.
     */
-    explicit WebViewWidget(Window& windowToMapTo);
+    explicit WebViewWidget(Window& windowToMapTo, bool initLater = false);
 
    /**
       Destructor.
@@ -55,11 +55,13 @@ public:
     void reload();
 
 protected:
+    void init(const char* initialJS);
+
     virtual void onMessage(char* message);
     void onResize(const ResizeEvent& ev) override;
 
 private:
-    const DISTRHO_NAMESPACE::WebViewHandle webview;
+    DISTRHO_NAMESPACE::WebViewHandle webview;
     void idleCallback() override;
     void onDisplay() override {}
 
diff --git a/dgl/src/Web.cpp b/dgl/src/Web.cpp
index 8deef02d..822990fa 100644
--- a/dgl/src/Web.cpp
+++ b/dgl/src/Web.cpp
@@ -26,15 +26,15 @@
 
 START_NAMESPACE_DGL
 
-// -----------------------------------------------------------------------
+// --------------------------------------------------------------------------------------------------------------------
 
-WebViewWidget::WebViewWidget(Window& windowToMapTo)
+WebViewWidget::WebViewWidget(Window& windowToMapTo, bool initLater)
     : TopLevelWidget(windowToMapTo),
-      webview(webViewCreate(windowToMapTo.getNativeWindowHandle(),
-                            windowToMapTo.getWidth(),
-                            windowToMapTo.getHeight(),
-                            windowToMapTo.getScaleFactor(),
-                            WebViewOptions(_on_msg, this)))
+      webview(initLater ? nullptr : webViewCreate(windowToMapTo.getNativeWindowHandle(),
+                                                  windowToMapTo.getWidth(),
+                                                  windowToMapTo.getHeight(),
+                                                  windowToMapTo.getScaleFactor(),
+                                                  WebViewOptions(_on_msg, this)))
 {
    #if !(defined(DISTRHO_OS_MAC) || defined(DISTRHO_OS_WINDOWS))
     if (webview != nullptr)
@@ -53,6 +53,24 @@ WebViewWidget::~WebViewWidget()
     }
 }
 
+void WebViewWidget::init(const char* const initialJS)
+{
+    DISTRHO_SAFE_ASSERT_RETURN(webview == nullptr,);
+
+    WebViewOptions options(_on_msg, this);
+    options.initialJS = initialJS;
+    webview = webViewCreate(getWindow().getNativeWindowHandle(), getWidth(), getHeight(), getScaleFactor(), options);
+
+    // FIXME implement initialJS
+    if (webview != nullptr)
+        webViewEvaluateJS(webview, initialJS);
+
+   #if !(defined(DISTRHO_OS_MAC) || defined(DISTRHO_OS_WINDOWS))
+    if (webview != nullptr)
+        addIdleCallback(this, 1000 / 60);
+   #endif
+}
+
 void WebViewWidget::evaluateJS(const char* const js)
 {
     if (webview != nullptr)
@@ -87,7 +105,7 @@ void WebViewWidget::idleCallback()
     webViewIdle(webview);
 }
 
-// -----------------------------------------------------------------------
+// --------------------------------------------------------------------------------------------------------------------
 
 static void notImplemented(const char* const name)
 {
diff --git a/distrho/extra/WebViewImpl.hpp b/distrho/extra/WebViewImpl.hpp
index 38c7e802..142c6a8f 100644
--- a/distrho/extra/WebViewImpl.hpp
+++ b/distrho/extra/WebViewImpl.hpp
@@ -45,6 +45,11 @@ struct WebViewOptions {
       PositionOffset() : x(0), y(0) {}
     } offset;
 
+   /**
+      Set some JavaScript to evalute on every new page load.
+    */
+    const char* initialJS;
+
    /**
       Message callback triggered from JavaScript code inside the WebView.
     */
@@ -54,12 +59,14 @@ struct WebViewOptions {
     /** Constructor for default values */
     WebViewOptions()
       : offset(),
+        initialJS(nullptr),
         callback(nullptr),
         callbackPtr(nullptr) {}
 
     /** Constructor providing a callback */
     WebViewOptions(const WebViewMessageCallback cb, void* const ptr)
       : offset(),
+        initialJS(nullptr),
         callback(cb),
         callbackPtr(ptr) {}
 };
diff --git a/distrho/src/DistrhoUI.cpp b/distrho/src/DistrhoUI.cpp
index 2bb5200b..9edddc40 100644
--- a/distrho/src/DistrhoUI.cpp
+++ b/distrho/src/DistrhoUI.cpp
@@ -246,7 +246,11 @@ UI::UI(const uint width, const uint height, const bool automaticallyScaleAndSetA
               #else
                false
               #endif
-               )),
+               )
+              #if DISTRHO_UI_WEB_VIEW
+               , true
+              #endif
+               ),
       uiData(UI::PrivateData::s_nextPrivateData)
 {
 #if !DISTRHO_PLUGIN_HAS_EXTERNAL_UI
@@ -269,7 +273,7 @@ UI::UI(const uint width, const uint height, const bool automaticallyScaleAndSetA
 #endif
 
   #if DISTRHO_UI_WEB_VIEW
-    evaluateJS(
+    init(
 "editParameter=function(index,started){window.webkit.messageHandlers.external.postMessage('editparam '+index+' '+(started ? 1 : 0))};"
 "setParameterValue=function(index,value){window.webkit.messageHandlers.external.postMessage('setparam '+index+' '+value)};"
    #if DISTRHO_PLUGIN_WANT_STATE