TextPatch.h File Reference

The TextPatch type and applyPatches function form the editor's canvas-to-text writeback sideband. When a tool mutates an attribute via EditorApp::applyMutation, it also produces a TextPatch that describes the corresponding byte-level splice in the source text. The main loop drains pending patches after flushFrame() and before rendering the source pane. More...

#include <cstddef>
#include <cstdint>
#include <span>
#include <string>
#include <string_view>
#include <vector>

Include dependency graph for TextPatch.h:

This graph shows which files directly or indirectly include this file:

Classes
struct	donner::editor::TextPatch
	A byte-level splice in the source text buffer. More...
struct	donner::editor::ApplyPatchesResult
	Result of an applyPatches call. More...

Namespaces
namespace	donner
	Top-level Donner namespace, which is split into different sub-namespaces such as donner::svg and donner::css.

Functions
ApplyPatchesResult	donner::editor::applyPatches (std::string &source, std::span< const TextPatch > patches)
	Apply a batch of TextPatch values to a source string.

Detailed Description

The TextPatch type and applyPatches function form the editor's canvas-to-text writeback sideband. When a tool mutates an attribute via EditorApp::applyMutation, it also produces a TextPatch that describes the corresponding byte-level splice in the source text. The main loop drains pending patches after flushFrame() and before rendering the source pane.

See docs/design_docs/structured_text_editing.md M3 for the full design.

Function Documentation

applyPatches()

ApplyPatchesResult donner::editor::applyPatches	(	std::string &	source,
		std::span< const TextPatch >	patches )

Apply a batch of TextPatch values to a source string.

Patches are sorted by descending offset before application so each splice doesn't shift the byte offsets of subsequent patches. Patches that would read past the end of the current string are rejected (counted in result.rejectedBounds). The remaining patches are applied in place.

Parameters

source	The mutable source text. Modified in place.
patches	The patches to apply. Order does not matter — the function sorts internally.

Returns

Summary of how many patches were applied vs. rejected.