How to change mobile keyboard orientation without changing device orientation

Question

I am working on a mobile app for IOS and Android in Unity, it needs to swap between screen orientations, landscape to portrait, with input text in both orientations. The transition-animations in iOS and Android are awkward to get around without looking ugly, so I would rather try to keep the device in landscape orientation, rotate the portrait sections of the app by 90 degrees, and tell the game to open the portrait-mode keyboard while the device is still in landscape orientation. Input text is required in both portrait and landscape scenes, so I need to be able to choose which orientation the keyboard popup is in.

I have only worked in mobile development through unity, so I do not know if this is this possible with the operating system's specific development resources like Xcode. To my knowledge you cannot disable android's screen-reorientating animation so this may be the only way to get around it. Any pointers for scripting in Android or iOS would be appreciated as well.

• derHugo: I doubt you can force overwrite the device orientation but only partially / selectively
• Adam B: I strongly doubt iOS would ever let you do this. Android possibly, but also doubtful. If this is absolutely necessary for your app, you might consider creating your own keyboard. But beware! the built-in keyboards are heavily user tested and extremely bug free. I would also ask, why spend time on this when you could be making your app better? Don't reinvent the wheel unless you absolutely need to :D
• Community: Please provide enough code so others can better understand or reproduce the problem.