Prior to this commit it was possible for the WebBrowserComponent
implementation on Windows to end up in an infinite loop if multiple
WebBrowserComponent objects were being created at the same time.
When an instance was already being created, the createWebView() call for
the second would place it in a queue and return without initiating its
creation. When the first WebView finishes creation, it calls the
handleAsyncUpdate() function of the second. However handleAsyncUdpate()
would see that the webViewBeingCreated helper variable was already true
and not call createWebView(), hence the second WebView would never be
created.
If, in the meantime, the scriptsWaitingForExecution variable wasn't
empty, handleAsyncUpdate() would endlessly call triggerAsyncUpdate().
WebView2 can emit COREWEBVIEW2_WEB_ERROR_STATUS_CONNECTION_ABORTED
errors during page navigation, even if the page navigation would happen
correctly afterwards. In such situations our internal error handler can
recursively encounter this error when trying to navigate to the error
handler page.
Prior to this commit the implementation could end up in an infinite loop
receiving the error and then navigating to the error handler page.
The handling of two state variables had to be adjusted. One is
responsible for signalling that we navigated to a blank page due to the
WebBrowserComponent becoming invisible. The other variable in the
WebView2 implementation stores the URL that we should be navigating to
once the WebView2 instance has been created.
Prior to this commit navigating to the URL requested by goToURL could
fail for two reasons: either because it was called before the underlying
WebView2 instance was created, or because the WebBrowserComponent was
not yet visible.
The default background colour of the WebBrowserComponent is white on all
platforms. Before the first page finishes loading this is the colour
that should fill the WebBrowserComponent's area.
Prior to this change however, on Windows a sudden flash to the default
JUCE background colour would occur, before the default white background
could take effect.
At the time of this commit there is a known issue with the
icorewebview2controller2, where a white flash is inevitable, unless the
WEBVIEW2_DEFAULT_BACKGROUND_COLOR environment variable is set. Using
a white background behind the WebView avoids this issue.
