InputText: Fixed undo/redo state corruption when editing buffer in user callback. (#4947, #4949)

This commit is contained in:
Joshua Webb 2022-01-27 22:02:24 +11:00 committed by ocornut
parent 23a785aeb3
commit 530332dfbc

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@ -3929,6 +3929,48 @@ static bool InputTextFilterCharacter(unsigned int* p_char, ImGuiInputTextFlags f
return true;
}
static inline void InputTextUpdateUndoStateAfterUserCallback(ImGuiInputTextState *state, const char *new_buf) {
// Find the shortest single replacement we can make to get the new text
// from the old text.
ImWchar *old_buf = state->TextW.Data;
int old_length = state->CurLenW;
int new_length = ImTextCountCharsFromUtf8(new_buf, NULL);
int shorter_length = ImMin(old_length, new_length);
int where = 0;
while (where < shorter_length) {
unsigned int b;
ImTextCharFromUtf8(&b, new_buf + where, NULL);
if (old_buf[where] != b)
break;
where += 1;
}
int old_last_diff = old_length - 1;
int new_last_diff = new_length - 1;
while (old_last_diff >= where && new_last_diff >= 0) {
unsigned int b;
ImTextCharFromUtf8(&b, new_buf + new_last_diff, NULL);
if (old_buf[old_last_diff] != b)
break;
old_last_diff -= 1;
new_last_diff -= 1;
}
int insert_len = new_last_diff - where + 1;
int delete_len = old_last_diff - where + 1;
if (insert_len > 0 || delete_len > 0) {
STB_TEXTEDIT_CHARTYPE *p = stb_text_createundo(&state->Stb.undostate, where, delete_len, insert_len);
if (p) {
for (int i=0; i < delete_len; ++i)
p[i] = ImStb::STB_TEXTEDIT_GETCHAR(state, where + i);
}
}
}
// Edit a string of text
// - buf_size account for the zero-terminator, so a buf_size of 6 can hold "Hello" but not "Hello!".
// This is so we can easily call InputText() on static arrays using ARRAYSIZE() and to match
@ -4516,6 +4558,7 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
if (buf_dirty)
{
IM_ASSERT(callback_data.BufTextLen == (int)strlen(callback_data.Buf)); // You need to maintain BufTextLen if you change the text!
InputTextUpdateUndoStateAfterUserCallback(state, callback_data.Buf);
if (callback_data.BufTextLen > backup_current_text_length && is_resizable)
state->TextW.resize(state->TextW.Size + (callback_data.BufTextLen - backup_current_text_length));
state->CurLenW = ImTextStrFromUtf8(state->TextW.Data, state->TextW.Size, callback_data.Buf, NULL);