I am able to reply fine without crazy scrolling on iPad, it’s just the positioning that can be improved,
The behaviour is to turn the fixed panel to an absolutely positioned element, it is the only thing we can do
Try replying to post #1 on a 200 post topic, or creating a new topic on iPad, both are functional
I can sort out the modals tomorrow as well, did not touch them yet
I am getting the same thing as @codinghorror did in the screenshot above. If I type into the box, it then hides way below the keyboard.
Try again, here on meta, it is now deployed.
I also added a hack so uploading images is possible.
Keep in mind, stuff is a bit quirky there is a limit to what I can do before completely giving up on fixed positioning and using full screens dialogs for absolutely everything.
This is totally just a stopgap till they get this fixed
there are still some things I can do to hold back the scroll event, but its all tricky.
One annoyance is that now on mobile Safari on iPhone 6, when I hit upload it is hiding behind the keyboard, I guess you can not win all battles
Also I need to fix it so you move around composer, it’s such a fragile beast
I think the fix for that is to have bootbox position from top instead of bottom.
its not bootbox, its a native control ios is rendering behind the keyboard in its infinite wisdom, fix is probably to ensure blur when upload is clicked.
Ok, got rid of the repositioning hack, it was fighting too hard with other hacks.
This means the composer no longer moves around when keyboard is open, it’s about as good as we can have it.
I spoke way too soon latest round of fixed made mobile far betterer
Also in other news, this is just as broken on iOS 9
A bunch more fixes went in today, I am still able to reproduce some weird, in particular
That said a lot is fixed, uploads on mobile work again, for the first time ever you can even upload multiple files in one post 
Composer window on iPhone is way bigger when typing, which is awesome
You can scroll around while typing and not lose your text area
So… Progress, next up is a route transition prior to composing, but it’s going to have to wait a bit
Interestingly, the latest release of my discourse installation is showing a much smaller text field at the composer as this meta.discourse.org community. It’s pretty annoying to see just about 4-5 lines. Here: 11 lines
Latest iOS version on iPad mini 4 (landscape mode)
Any clue to solve this issue?
Yep this is because it is impossible to detect size of mobile keyboard so we have to assume smallest device.
How can I change the size of the composer?
I think the composer is one of the most important modules of Discourse. The usability plays an important role, especially for tablet users.
Why is this the case? Every browser tells you how the current screen size is and the orientation is also detectable for many websites. The composer could get half of the screen size. 50% of the screen is always filled with the keyboard.
It is sometimes significantly more than 50% and sometimes less. Unless the browser can detect mobile keyboard size it is impossible to know.
You can set it how you like with CSS but you will potentially be obscuring screen on smaller devices.
Can you (or someone else) help me with a CSS snippet? 
Wait a moment, do you have any screenshot of where we are taking less than 50% when focused?
Basically show me some screenshots of what you perceive to be problems with the name of browser / device.
We changed it since you worked on it, as 50% isn’t correct. Users were complaining the editor was obscured. There is no known way to determine the size of the viewport with the mobile keyboard expanded.
I follow, just interested in seeing some screenshot where it egregiously wrong, I am not sure size can be overridden with CSS.
