How to grab the scrolling amount in one window? - scroll

Question

This is the first step to scroll two windows simulteneously, the second step is to find a way to apply that amount to the other program. But I really don't know where to start, all I see in from Google is about modifying the behavior of the scroll of the mouse, not the scrolling amount in one window. Advantages of using this instead of listening to the keys:
Scrolling will be seamless since the other program are scrolled in the background
Clicking on the scrollbar works
Different scrolling speeds don't affect the comparison
Moving lines in text editors won't scroll pages in PDF viewers

Answer 1

I can tell you what I would do, but it's not going to be fun...
Assuming the text is roughly evenly distributed (which it might not be between two languages like that, and two windows with different text sizes and widths, really consider this carefully before you do the work), then the goal is to force both scroll bars to be at the same percent relative to their whole. So what you need to do is write a function to determine what percent each scroll bar is at. I would screen capture both windows and crop out the important parts of the scroll bar like this:
Specifically the up and down buttons, the top of the scroll handle, the bottom of the scroll handle. Save them in their own files. Do it for both windows in case they draw their scroll bars a little differently.
Now the tricky part. Write a function that does the following: imagesearch for the top button within rightmost 25 pixels or of the specified window. Same for the bottom button. Same for the top of the handle. Same for the bottom of the handle. Use this to determine where your window is.
SetTitleMatchMode, 2 ; so it matches the end of the title
WinGetPos , X, Y, Width, Height, LibreOffice Writer ;exact substring of window name required
Use something like this to find the scroll bar parts.
CoordMode, Pixel , Screen ;so image search searches entire screen
barwidth = 25 ; make sure it's more than the bar is wide.
ImageSearch, TopButtonX, TopButtonY, X+Width-barwidth , Y, X+Width, Y+Height, TopButton.bmp ; no jpg, fuzzy edges make searches fail
Then do some math, something like:
TopButtonY := TopButtonY+TopButtonImageHeight ; because we only care about the position of the bottom of the button.
BottomHandleY := BottomHandleY+BottomHandleImageHeight ; because we only care about where the bottom of the handle is.
HandleHeight := TopHandleY - BottomHandleY ; how tall the scroll handle is
TotalHeight := TopButtonY - BottomButtonY - HandleHeight ;how tall the scroll field is
HandleOffset := TopHandleY - TopButtonY ;how far it is from the top
HandlePercent := HandleOffset / TotalHeight ; the part we care about. return this value
With a function like that, you can know how scrolled each window is. All that's left is to send the scroll commands. There's a few choices.
; ControlSend , Control, Keys, LibreOffice Writer
ControlSend , Control, {Pgdown}, LibreOffice Writer ; or {Pgup}
ControlSend , Control, {WheelUp}, LibreOffice Writer ; or {wheeldown}
ControlSend , Control, {Up}, LibreOffice Writer ; or {down}
If it lets you move the caret with up/down arrows while the window is inactive, that is probably the most precise option, even if it takes a bit longer. The fastest most precise way is to simulate a click drag also using control send. To use ControlSend you need to figure out which control you're working on. WindowSpy can help you with that.
So first: Find the scroll positions of both windows. Second determine which window is active. Third, nudge the inactive window in the correct direction. Repeat until they're within a certain tolerance range (otherwise it will bounce up and down endlessly).
I can't emphasize this enough, but please make sure that getting the scroll bars in approximately the same positions is sufficiently close before even attempting this. If it isn't, you will have wasted a lot of time fiddling with it. Keep in mind it will be less and less accurate the longer the text is.
If it is an option, I would definitely consider copying the contents of both windows into a program that gives you more access to the controls (or better one that is specialized for this purpose). If you had more access, you could use the paragraph breaks to line up the texts with far more precision.
If you really just want to see both texts side by side (and the paragraphs do line up), you could find a text editor that tells you information like this:
If autohotkey will let you read the text of that information, you can copy the PDF into autohotkey's memory (separated by line) and use autohotkey to show only the corresponding paragraph of the PDF as you move around in the editable document.
Hope something I said helps, good luck.