Scale web view based on a MaxHeight

This is related to our on going problems described in #10. We now allow
web to have a max height, that means that semantic zoom will never zoom
over maxheight pixels. The rest of the scaling is done by bitmap
scaling in QML. This is all controlled by the webMaxHeight property set
in main.cpp

src/main.cpp

@@ -236,6 +236,17 @@ int main(int argc, char *argv[])
     KonvergoWindow::RegisterClass();
     engine->rootContext()->setContextProperty("components", &ComponentManager::Get().getQmlPropertyMap());
 
+    // This controls how big the web view will zoom using semantic zoom
+    // over a specific number of pixels and we run out of space for on screen
+    // tiles in chromium. This only happens on OSX since on other platforms
+    // we can use the GPU to transfer tiles directly.
+    // See more discussion in: https://github.com/plexinc/plex-media-player/issues/10
+#ifdef Q_OS_MAC
+    engine->rootContext()->setContextProperty("webMaxHeight", 1080);
+#else
+    engine->rootContext()->setContextProperty("webMaxHeight", 0);
+#endif
+
     // the only way to detect if QML parsing fails is to hook to this signal and then see
     // if we get a valid object passed to it. Any error messages will be reported on stderr
     // but since no normal user should ever see this it should be fine

src/ui/webview.qml

@@ -12,6 +12,13 @@ KonvergoWindow
   minimumHeight: 720
   minimumWidth: 1280
 
+  function getMaxHeightArg()
+  {
+    if (webMaxHeight > 0)
+      return "?maxHeight=" + webMaxHeight
+    return ""
+  }
+
   MpvVideo
   {
     id: video
@@ -26,13 +33,27 @@ KonvergoWindow
   {
     id: web
     objectName: "web"
-    width: Math.min((parent.height * 16) / 9, parent.width)
-    height: Math.min((parent.width * 9) / 16, parent.height)
-    anchors.centerIn: parent
+    anchors.fill: parent
     settings.errorPageEnabled: false
     settings.localContentCanAccessRemoteUrls: true
     profile.httpUserAgent: components.system.getUserAgent()
-    url: components.settings.value("path", "startupurl")
+    url: components.settings.value("path", "startupurl") + getMaxHeightArg()
+    transformOrigin: Item.TopLeft
+    scale:
+    {
+      if (webMaxHeight == 0)
+        return 1;
+
+      if (height > webMaxHeight)
+      {
+        return height / webMaxHeight;
+      }
+      else
+      {
+        return 1;
+      }
+    }
+    smooth: true
 
     Component.onCompleted:
     {
@@ -101,6 +122,7 @@ KonvergoWindow
     }
   }
 
+
   Rectangle
   {
     id: debug
@@ -125,7 +147,17 @@ KonvergoWindow
       color: "white"
       font.pixelSize: width / 45
 
-      text: mainWindow.debugInfo
+      function windowDebug()
+      {
+        var dbg = mainWindow.debugInfo + "Window and web\n";
+        dbg += "  Window size: " + parent.width + "x" + parent.height + "\n";
+        dbg += "  Web Max Height: " + webMaxHeight + "\n";
+        dbg += "  Web scale: " + Math.round(web.scale * 100) / 100;
+
+        return dbg;
+      }
+
+      text: windowDebug()
     }
 
     Text