P0-01: Prompt to save unsaved changes on close/quit

[hybridmachine]

Description

Check SCI_GETMODIFY in windowShouldClose: and applicationShouldTerminate:. Present Save/Don't Save/Cancel alert for each dirty buffer.

Implementation

• In windowShouldClose:, iterate all tabs and check SCI_GETMODIFY for each buffer
• Show NSAlert with Save/Don't Save/Cancel buttons for each dirty document
• Cancel aborts close; Don't Save discards; Save triggers save flow
• In applicationShouldTerminate:, same logic but for app quit
• Handle split view buffers (check both views)

Key Files

• macos/platform/main_phase7.mm

Sprint

Sprint 1 - Data Safety

[hybridmachine]

Detailed Implementation Plan

Overview

Currently, closing a tab, closing all tabs, closing the window, or quitting the app all proceed without checking for unsaved changes. This plan adds save prompts at all four close/quit paths, following macOS platform conventions (NSAlert with Save/Don't Save/Cancel).

---

1. New File: macos/platform/save_prompt.h/mm

Create a dedicated module for save-prompt logic. This keeps the alert UI and dirty-buffer iteration out of the command dispatch and app delegate.

Header (save_prompt.h):

#pragma once
#include <string>
#include <vector>

// Return values for save prompt
enum class SavePromptResult
{
    Save,       // User chose Save
    DontSave,   // User chose Don't Save
    Cancel      // User chose Cancel (abort the operation)
};

// Prompt for a single dirty document. Returns user's choice.
SavePromptResult promptSaveSingleDocument(const std::wstring& title);

// Check if a specific document (by view + tab index) is dirty.
// Saves current view state first so SCI_GETMODIFY reflects the active editor.
bool isDocumentDirty(int viewIndex, int tabIndex);

// Attempt to save a document by view + tab index.
// Temporarily switches active context if needed, calls saveCurrentFile(), then restores.
// Returns true if save succeeded (or file was already saved), false if user cancelled Save As dialog.
bool saveDocumentAt(int viewIndex, int tabIndex);

// Prompt-and-handle for closing a single tab. Returns true if close should proceed.
bool promptAndHandleClose(int viewIndex, int tabIndex);

// Prompt-and-handle for closing all tabs in a view. Returns true if close-all should proceed.
bool promptAndHandleCloseAll(int viewIndex);

// Prompt-and-handle for quitting the app (all tabs in all views). Returns true if quit should proceed.
bool promptAndHandleQuit();

Implementation (save_prompt.mm):

promptSaveSingleDocument(title)

• Creates an NSAlert with:
  • Message: "Do you want to save changes to [title]?"
  • Informative text: "Your changes will be lost if you don't save them."
  • Buttons: Save (1st/default), Don't Save (2nd), Cancel (3rd)
• Runs modal via [alert runModal]
• Maps NSAlertFirstButtonReturn → Save, Second → DontSave, Third → Cancel

isDocumentDirty(viewIndex, tabIndex)

• If the document is currently loaded in the Scintilla editor for that view, call saveViewState() first to sync modified flag from Scintilla → DocumentData.modified
• Then check docs[tabIndex].modified
• Also check: if the document is an untitled buffer with content (filePath.empty() && !content.empty()), treat as dirty even if modified == false (edge case for new unsaved files that haven't been edited since creation)

saveDocumentAt(viewIndex, tabIndex)

• If the document is not in the active view, temporarily switch context (save current view state, switch activeView, activeTab)
• Call saveCurrentFile() — this already handles Save As for untitled files
• Check if save actually succeeded (file path is now set and SCI_GETMODIFY returns 0)
• Restore original context if it was switched
• Return success/failure

promptAndHandleClose(viewIndex, tabIndex)

1. Call isDocumentDirty(viewIndex, tabIndex) — if clean, return true
2. Call promptSaveSingleDocument(docs[tabIndex].title)
3. If Save: call saveDocumentAt(viewIndex, tabIndex). If save fails (user cancelled Save As), return false
4. If Don't Save: return true
5. If Cancel: return false

promptAndHandleCloseAll(viewIndex)

1. Iterate all tabs in the view
2. For each dirty tab, call promptSaveSingleDocument()
3. If any tab returns Cancel, abort the entire close-all and return false
4. Save or skip each tab per user choice
5. Return true only if all tabs handled

promptAndHandleQuit()

1. Collect all dirty tabs across both views (view 0 documents + view 1 documents if split)
2. If no dirty tabs, return true
3. If exactly one dirty tab, prompt for that single document
4. If multiple dirty tabs, show a summary alert:
   • Message: "You have N unsaved documents. Save changes before quitting?"
   • Buttons: Save All, Don't Save, Review Each, Cancel
   • Save All: iterate and save each; if any Save As is cancelled, abort
   • Don't Save: return true
   • Review Each: call promptSaveSingleDocument() for each dirty document in sequence
   • Cancel: return false
5. Return result

---

2. Modify wndproc.mm — Hook Close Commands

IDM_FILE_CLOSE (line 73-75)

case IDM_FILE_CLOSE:
    if (promptAndHandleClose(ctx().activeView, ctx().activeTabIndex()))
        closeTabFromView(ctx().activeView, ctx().activeTabIndex());
    return 0;

IDM_FILE_CLOSEALL (lines 76-83)

case IDM_FILE_CLOSEALL:
{
    if (!promptAndHandleCloseAll(ctx().activeView))
        return 0; // user cancelled
    auto& closeDocs = ctx().activeDocuments();
    while (closeDocs.size() > 1)
        closeTabFromView(ctx().activeView, static_cast<int>(closeDocs.size()) - 1);
    closeTabFromView(ctx().activeView, 0);
    return 0;
}

WM_CLOSE (lines 363-366)

case WM_CLOSE:
    if (!promptAndHandleQuit())
        return 0; // user cancelled, don't close
    KillTimer(hWnd, IDT_STATUSBAR);
    PostQuitMessage(0);
    return 0;

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3. Modify app_delegate.mm — Intercept Window/App Close

Add windowShouldClose: delegate method

This is called when the user clicks the window's close button (red X). Currently not implemented — the default returns YES.

- (BOOL)windowShouldClose:(NSWindow*)sender
{
    return promptAndHandleQuit() ? YES : NO;
}

Replace applicationShouldTerminateAfterLastWindowClosed:

Currently returns YES. This should stay — but the window close is now guarded by windowShouldClose:.

Add applicationShouldTerminate: delegate method

This intercepts Cmd+Q and app-level quit requests (Dock menu quit, etc.). This is important because Cmd+Q doesn't go through windowShouldClose:.

- (NSApplicationTerminateReply)applicationShouldTerminate:(NSApplication*)sender
{
    if (promptAndHandleQuit())
        return NSTerminateNow;
    return NSTerminateCancel;
}

Note: With applicationShouldTerminate: implemented, the Cmd+Q path is handled. The WM_CLOSE handler in wndproc.mm handles the case where close is triggered programmatically via SendMessage(WM_CLOSE).

---

4. Update CMakeLists.txt

Add save_prompt.h and save_prompt.mm to the source list.

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5. Edge Cases to Handle

Scenario	Behavior
Untitled with content	Treat as dirty, prompt Save As
Untitled empty buffer	Not dirty, close silently
Save As cancelled	Abort the close/quit operation
Split view quit	Check both documents and documents2
Split view close-all	Only prompts for the active view's tabs
Single tab left	After prompt, resets to empty Untitled (existing behavior)
All docs clean	No prompt, proceed immediately
File write error	Show error alert, treat as cancel (don't lose data)

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6. Testing Plan

• Single dirty tab close — modify a file, Cmd+W → get prompt, verify Save/Don't Save/Cancel all work
• Clean tab close — close unmodified tab → no prompt
• Close All with mix — 3 tabs (1 dirty, 2 clean) → only prompted for the dirty one
• Quit with dirty tabs — Cmd+Q with unsaved changes → prompted, Cancel keeps app open
• Window close button — click red X with dirty tabs → prompted
• Save As on untitled — new file with content, quit → Save triggers Save As dialog
• Cancel Save As aborts quit — during quit prompt, choose Save, then cancel Save As → quit is aborted
• Split view quit — dirty tabs in both views → prompted for all
• Session still saved — after Don't Save quit, session.json reflects last saved state

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File Change Summary

File	Action
macos/platform/save_prompt.h	NEW — save prompt declarations
macos/platform/save_prompt.mm	NEW — save prompt implementation
macos/platform/wndproc.mm	MODIFY — guard IDM_FILE_CLOSE, IDM_FILE_CLOSEALL, WM_CLOSE
macos/platform/app_delegate.mm	MODIFY — add windowShouldClose:, applicationShouldTerminate:
macos/CMakeLists.txt	MODIFY — add save_prompt source files

Estimated Size: Small (S)

~200 lines of new code across 2 new files + ~20 lines of modifications to 3 existing files.

[hybridmachine]

Reviewed — strong foundation overall. I see a few gaps to tighten before implementation:

• Please avoid double prompting. Right now the plan hooks WM_CLOSE, windowShouldClose:, and applicationShouldTerminate:. These paths can stack and cause repeated alerts. Prefer a single authoritative prompt path (with a re-entry guard).
• In saveDocumentAt(...), avoid mutating activeView/activeTab directly. Use existing tab-switch/save-state helpers so Scintilla/document state stays consistent.
• For Close All / Quit, take a snapshot of dirty docs first. Iterating live vectors while saves/prompts change state can skip documents.
• Treat Save As cancel as hard cancel of the close/quit operation (no partial close).
• In split mode, decide whether same-path docs are one logical doc or separate prompts; if one, dedupe by canonicalized path.