overwriteinput

Overwriteinput is a software term used to describe a mode or flag that governs how new input is integrated into existing data. In practice, it usually controls whether typed characters replace the character at the current cursor position (overwrite mode) or are inserted, pushing existing content to the right (insert mode). The concept is common in text editors and input controls, where a boolean property named overwriteInput may be exposed, or where a UI toggle switches between behaviors. However, exact naming and scope vary by framework and platform.

In usage, enabling overwriteInput causes new input to overwrite the character or data at the insertion point, while disabling it results in standard insertion behavior. Handling selections can affect this behavior: when text is selected, new input may replace the selected range in a manner similar to typing, depending on implementation.

Implementation considerations include correct handling of multibyte or complex Unicode characters, maintaining cursor or caret position, and interactions with other operations such as paste, delete, and backspace. Edge cases arise at the end of a buffer or string, or when parts of the data are immutable or read-only.

Common patterns for implementing overwrite behavior involve checking the mode flag at input time and either replacing the existing data at the cursor or performing a standard insert. Pseudocode examples illustrate the basic dichotomy:

If overwriteInput is true, replace the data at the current position; otherwise, insert the new character at the position and advance the cursor.

Variants of the term appear in different ecosystems, sometimes as overwrite mode, insert/overwrite toggles, or similar flags. See also: insert mode, overwrite mode, caret, text buffer.