How to get and set TChromium
scrollbar positions in Delphi ?
To get or set the scroll position of an element, you follow these steps: First, select the element using the selecting methods such as querySelector() . Second, access the scroll position of the element via the scrollLeft and scrollTop properties.
If you want to set the scroll position of document. body , you can scroll the entire window altogether using window. scrollTo() ; it takes either a pair of coordinates (x,y) or an options object – if you just want to scroll nicely to the top, try window. scrollTo({top:0,behavior:'smooth'}); .
It's possible to work with javascript objects directly. Just use CefV8Context of the frame.
Here is an example:
var
val: ICefV8Value;
context: ICefv8Context;
excp: ICefV8Exception;
scroll: TPoint;
begin
if (Chromium1.Browser.MainFrame = nil) then
exit;
//this will work only with exact frame
context := Chromium1.Browser.MainFrame.GetV8Context;
if (context <> nil) then
begin
context.Eval('window.pageXOffset', val, excp);
scroll.x := val.GetIntValue;
context.Eval('window.pageYOffset', val, excp);
scroll.y := val.GetIntValue;
end
else
exit;
//todo: do something with scroll here
end;
Currently playing with CefSharp, I do think that this is similar than in Delphi. Here is my solution:
public int GetVerticalScrollPosition()
{
var r = _webView.EvaluateScript(@"document.body.scrollTop");
return Convert.ToInt32(r);
}
public void SetVerticalScrollPosition(int pos)
{
_webView.ExecuteScript(
string.Format(@"document.body.scrollTop = {0}", pos));
}
I'm not that Delphi expert anymore, hope you can understand my code; basically I use JavaScript to read/write the scroll positions and execute these small JavaScript snippets through the EvaluateScript
and ExecuteScript
methods.
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