How to detect non modifier key press combination?

delphi, keyboard-events, keyboard-shortcuts, onkeypress, textbox

Solution

Each individual keystroke generates separate `OnKeyDown`, `OnKeyPress`, and `OnKeyUp` events. So you have three choices:

keep track of each key that is currently held down. For each key you receive, set a flag for it in the `OnKeyDown` event and clear the flag for it in the corresponding `OnKeyUp` event. When you get an `OnKeyDown` event for D, check if you already flagged A, F, G, etc. The `OnKeyDown` and `OnKeyUp` events will also tell you the state of the CTRL, ALT, and SHIFT keys.

use the Win32 API `GetKeyboardState()`, `GetKeyState()` or `GetAsyncKeyState()` functions. When you get an `OnKeyDown` event for D, ask the OS if A, F, G, CTRL, etc are currently held down.

for some sequences, you might use `RegisterHotKey()` and let the OS track the keys for you. When a registered sequence is detected, you will receive a `WM_HOTKEY` message.

Problem

I have the following problem in Delphi (but it might be taken as a general programming question). I would like to handle somehow a key press event for more than one non-modifier key combination, for example for shortcuts like A+D or D+F or D+F+G. I know how to handle shortcuts with modifier keys like for instance CTRL+D or CTRL+ALT+D or ALT+D, but how can I detect non-modifier key press combination ?

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