P1-08: Printing via macOS print system

[hybridmachine]

Description

Print document content via macOS native print system.

Implementation

• File menu: Print (Cmd+P)
• Create NSPrintOperation from Scintilla content
• Option 1: Extract text and render via NSTextView for printing
• Option 2: Use Scintilla's SCI_FORMATRANGE if available on macOS
• Include line numbers option
• Header with filename, date, page numbers
• Print preview via standard macOS print dialog

Key Files

• macos/platform/main_phase7.mm
• macos/platform/scintilla_bridge.h

Sprint

Sprint 8 - Content & Views

[hybridmachine]

Implementation Plan

Overview

Implement native macOS printing support for MacNote++ so users can print the current document via File > Print... (Cmd+P). The approach extracts text from the Scintilla editor buffer, builds an NSAttributedString with monospace formatting, and renders it through a custom NSView subclass that handles pagination, headers (filename + date), footers (page numbers), and optional line numbers. The standard macOS NSPrintOperation sheet provides print preview and printer selection out of the box.

Step-by-step Implementation

Step 1: Add the IDM_FILE_PRINT command constant

• File: macos/platform/npp_constants.h
• Changes: Add a new constant for the print command ID.
• Code sketch:

#define IDM_FILE_PRINT 41020

Step 2: Add Print menu item to the File menu

• File: macos/platform/menu_builder.mm
• Changes: Insert a "Print..." item with Cmd+P into the File menu, placed before the Close group (after the Copy Path items).
• Code sketch:

AppendMenuW(hFileMenu, MF_SEPARATOR, 0, nullptr);
AppendMenuW(hFileMenu, MF_STRING, IDM_FILE_PRINT, L"&Print...\tCtrl+P");

Step 3: Create print_support.h — header for print functionality

• File: macos/platform/print_support.h (NEW)
• Changes: Declare the public interface for invoking print.
• Code sketch:

#pragma once
#import <Cocoa/Cocoa.h>

// Entry point — call from WM_COMMAND handler
void showPrintDialog(NSWindow *parentWindow);

Step 4: Create NppPrintView and printing logic in print_support.mm

• File: macos/platform/print_support.mm (NEW)
• Changes: Implement the full print pipeline. Key components:

4a. Text extraction from Scintilla

static NSString *extractScintillaText()
{
    auto sciView = ctx().activeScintillaView();
    if (!sciView) return @"";

    intptr_t len = ScintillaBridge_sendMessage(sciView, SCI_GETTEXTLENGTH, 0, 0);
    if (len <= 0) return @"";

    std::vector<char> buf(len + 1, 0);
    ScintillaBridge_sendMessage(sciView, SCI_GETTEXT, len + 1,
        reinterpret_cast<intptr_t>(buf.data()));
    return [NSString stringWithUTF8String:buf.data()];
}

4b. Optional line-number prefixing

static NSString *addLineNumbers(NSString *text)
{
    NSArray<NSString *> *lines = [text componentsSeparatedByString:@"\n"];
    NSMutableString *result = [NSMutableString string];
    int width = (int)ceil(log10((double)lines.count + 1));
    for (NSUInteger i = 0; i < lines.count; ++i)
    {
        [result appendFormat:@"%*lu  %@\n", width, (unsigned long)(i + 1), lines[i]];
    }
    return result;
}

4c. NppPrintView : NSView subclass

Custom view handling pagination and page-level rendering:

@interface NppPrintView : NSView
{
    NSAttributedString *_content;
    NSString *_fileName;
    NSDate *_printDate;
    NSFont *_bodyFont;
    NSFont *_headerFont;
    CGFloat _headerHeight;
    CGFloat _footerHeight;
    NSLayoutManager *_layoutManager;
    NSTextStorage *_textStorage;
    NSTextContainer *_textContainer;
    NSArray<NSValue *> *_pageRanges;
}
- (instancetype)initWithContent:(NSString *)text
                       fileName:(NSString *)name
                           font:(NSFont *)font;
@end

Implementation:

• initWithContent:fileName:font: — Stores filename, date, fonts. Creates NSAttributedString with monospace body font. Initializes NSTextStorage + NSLayoutManager for pagination.
• knowsPageRange: — Reads printable area from NSPrintInfo, subtracts header/footer heights. Configures NSTextContainer to body size. Forces layout. Walks glyph ranges line by line, accumulating until body height exceeded, starts new page. Stores glyph range per page. Returns total page count.
• rectForPage: — Returns full bounds rect.
• drawRect: — Determines current page from NSPrintOperation. Draws header (filename left, date right, gray separator line). Draws body text via NSLayoutManager drawGlyphsForGlyphRange:atPoint:. Draws footer with centered page number ("Page 3 of 12").

4d. showPrintDialog entry point

void showPrintDialog(NSWindow *parentWindow)
{
    NSString *text = extractScintillaText();
    if (text.length == 0) return;

    NSString *fileName = @"Untitled";
    auto &docs = ctx().activeDocuments();
    int idx = ctx().activeTabIndex();
    if (idx >= 0 && idx < (int)docs.size())
        fileName = WideToNSString(docs[idx].title.c_str());

    NSFont *font = [NSFont fontWithName:@"Menlo" size:10.0];
    if (!font)
        font = [NSFont monospacedSystemFontOfSize:10.0 weight:NSFontWeightRegular];

    NppPrintView *printView = [[NppPrintView alloc]
        initWithContent:text fileName:fileName font:font];

    NSPrintInfo *printInfo = [NSPrintInfo sharedPrintInfo];
    [printInfo setTopMargin:50.0];
    [printInfo setBottomMargin:40.0];
    [printInfo setLeftMargin:40.0];
    [printInfo setRightMargin:40.0];
    [printInfo setHorizontalPagination:NSPrintingPaginationModeFit];
    [printInfo setVerticalPagination:NSPrintingPaginationModeAutomatic];

    NSPrintOperation *op = [NSPrintOperation printOperationWithView:printView
                                                          printInfo:printInfo];
    [op setShowsPrintPanel:YES];
    [op setShowsProgressPanel:YES];
    [op runOperationModalForWindow:parentWindow
                          delegate:nil didRunSelector:nil contextInfo:nil];
}

Step 5: Handle IDM_FILE_PRINT in wndproc.mm

• File: macos/platform/wndproc.mm
• Changes: Add a case in WM_COMMAND dispatch for IDM_FILE_PRINT.
• Code sketch:

#include "print_support.h"
// ...
case IDM_FILE_PRINT:
    showPrintDialog(ctx().mainWindow);
    break;

Step 6: Register source file in CMakeLists.txt

• File: macos/CMakeLists.txt
• Changes: Add platform/print_support.mm to the source file list.

Step 7: (Optional) Line-number toggle in print accessory view

• File: macos/platform/print_support.mm
• Changes: Create an NSView with an NSButton checkbox labeled "Show line numbers" and attach as print panel's accessory view. Can be deferred to follow-up.

Design Decisions

Decision	Choice	Rationale
Text extraction	SCI_GETTEXT for full buffer as UTF-8	Simpler and more reliable than SCI_FORMATRANGE, which has inconsistent macOS Cocoa Scintilla support
Rendering	NSLayoutManager + NSTextContainer in custom NSView	Precise control over pagination, headers, footers using native Cocoa text layout
Print font	Menlo 10pt (fallback: monospacedSystemFont)	Monospace expected for code editor; Menlo ships with macOS; 10pt readable on paper
View approach	Custom NppPrintView with knowsPageRange:/drawRect:	Full control over page layout including header/footer
Line numbers	Optional, prefix-based (prepend to text)	Simplest approach, avoids custom gutter drawing
Dialog presentation	Sheet on ctx().mainWindow	Standard macOS UX, non-blocking
Shortcut	Cmd+P	Universal macOS print shortcut
Margins	Top 50, Bottom 40, Left/Right 40 points	Comfortable margins; header/footer fit within top/bottom

Edge Cases

Scenario	Expected Behavior
Empty document	showPrintDialog returns early, no dialog shown
Very large document (100K+ lines)	Progress panel shows activity; no truncation
Untitled document	Header displays "Untitled"
Non-UTF-8 / binary content	Nil from stringWithUTF8String caught, treated as empty
Very long lines (no wrap)	NSPrintingPaginationModeFit scales to page width
User cancels print dialog	NSPrintOperation handles natively, no cleanup needed
No printers configured	macOS shows Save as PDF and other options
Tabs in source code	NSLayoutManager uses default tab stops; future enhancement could match editor tab width

Testing Plan

• Basic print: Open file, Cmd+P, verify preview shows content correctly
• Header/footer: Verify filename top-left, date top-right, page number bottom-center
• Multi-page: 500+ line file, verify correct pagination with no missing/duplicated text
• Empty document: Cmd+P on empty tab — no dialog, no crash
• Untitled document: New tab with typed content — header shows "Untitled"
• Line numbers: Verify correct numbering and right-alignment
• Unicode content: CJK, emoji render correctly
• Print to PDF: Save as PDF, verify valid output
• Cancel: Open dialog, cancel — no crash or side effects
• Menu item: Print... in File menu with Cmd+P, enabled when document open
• Long lines: 300+ char lines handled without clipping

File Change Summary

File	Action
macos/platform/npp_constants.h	MODIFY — add IDM_FILE_PRINT
macos/platform/menu_builder.mm	MODIFY — add Print... menu item
macos/platform/print_support.h	NEW — public API
macos/platform/print_support.mm	NEW — NppPrintView, extraction, showPrintDialog()
macos/platform/wndproc.mm	MODIFY — add IDM_FILE_PRINT case
macos/CMakeLists.txt	MODIFY — add print_support.mm

Estimated Size

Medium — ~300-400 lines of new code across 2 new files, plus small changes to 4 existing files. Bulk is in print_support.mm (custom view pagination/rendering). Estimated 1-2 days.

[hybridmachine]

Good feature direction, but this feels over-scoped for a first delivery.

Suggested path:

• MVP first: wire File > Print... and use native NSPrintOperation for the active document text.
• Defer custom pagination/header/footer/line-number accessory until baseline print behavior is stable.

Implementation notes:

• Use current editor font settings (ctx().fontName, ctx().fontSize) instead of hardcoded Menlo 10.
• Ensure split-view correctness by printing from ctx().activeScintillaView().
• Wire through existing AppendMenuW + wndproc.mm command dispatch path.
• Optional: align print command naming/ID with upstream IDM_FILE_PRINT for easier future sync.

[hybridmachine]

Amended Implementation Plan

Thanks for the review feedback — all good points. Here's the revised plan, restructured to land a minimal working print path first.

Addressing Feedback

1. Over-scoped: Agreed. The custom NppPrintView with headers/footers/line-numbers is premature. Phase 1 will use NSTextView which already handles print pagination out of the box.
2. Font settings: Will use ctx().fontName / ctx().fontSize instead of hardcoded Menlo 10. Falls back to monospacedSystemFontOfSize: if the named font isn't available.
3. Split-view correctness: Will extract text from ctx().activeScintillaView(), not assume a single editor.
4. Command dispatch: Will wire through the existing AppendMenuW + wndproc.mm path — no new dispatch mechanism.
5. Command ID alignment: Will use IDM_FILE_PRINT = 41020 to match upstream Notepad++.

---

Phase 1 — MVP (this sprint)

Goal: File > Print… works, prints active document text with correct font, using native macOS print dialog.

Key insight: NSTextView already handles pagination for printing. We just set the text and font on an off-screen NSTextView and hand it to NSPrintOperation. No custom print view needed.

Files changed:

File	Change
macos/src/npp_constants.h	Add IDM_FILE_PRINT = 41020
macos/src/menu_builder.mm	Add "Print...\tCtrl+P" menu item via AppendMenuW under File menu
macos/src/print_support.h	Declare showPrintDialog(NSWindow *parentWindow)
macos/src/print_support.mm	Implement MVP print (see sketch below)
macos/src/wndproc.mm	Handle IDM_FILE_PRINT → call showPrintDialog(ctx().mainWindow)
macos/CMakeLists.txt	Add print_support.mm to sources

MVP implementation sketch:

void showPrintDialog(NSWindow *parentWindow)
{
    auto sci = ctx().activeScintillaView();
    if (!sci) return;

    intptr_t len = ScintillaBridge_sendMessage(sci, SCI_GETTEXTLENGTH, 0, 0);
    if (len <= 0) return;

    std::vector<char> buf(len + 1, 0);
    ScintillaBridge_sendMessage(sci, SCI_GETTEXT, len + 1, (intptr_t)buf.data());
    NSString *text = [NSString stringWithUTF8String:buf.data()];
    if (!text) return;

    NSFont *font = [NSFont fontWithName:
        [NSString stringWithUTF8String:ctx().fontName.c_str()]
        size:ctx().fontSize];
    if (!font)
        font = [NSFont monospacedSystemFontOfSize:ctx().fontSize weight:NSFontWeightRegular];

    NSTextView *printView = [[NSTextView alloc] initWithFrame:NSMakeRect(0, 0, 612, 792)];
    [printView setFont:font];
    [printView setString:text];

    NSPrintOperation *op = [NSPrintOperation printOperationWithView:printView];
    [op setShowsPrintPanel:YES];
    [op setShowsProgressPanel:YES];
    [op runOperationModalForWindow:parentWindow
                          delegate:nil didRunSelector:nil contextInfo:nil];
}

---

Phase 2 — Future Sprint

• Custom NppPrintView with header/footer/page numbers
• Line number gutter option via print accessory view
• Custom pagination control
• Syntax-highlighted printing (pulling styled text from Scintilla)

Phase 2 will only start once Phase 1 is stable and merged.