README

Caption Switcher

A lightweight Windows utility built entirely in Object Pascal using raw Win32 API calls (no VCL) that enumerates all visible top-level windows and allows the user to change their title bar text (caption) in real-time. The entire application is a single .dpr file with zero runtime library dependencies. This project was developed for educational purposes and is no longer actively maintained (discontinued 2013-03-28).

Features

• Window Enumeration -- uses EnumWindows with a custom callback to discover all visible, top-level windows (excluding toolwindows and child windows), populating a sorted listbox
• Caption Modification -- changes any window's title bar text using FindWindowA and SetWindowTextA, applying the new caption immediately
• Zero-VCL Architecture -- the entire UI is built with raw Win32 API calls: CreateWindowExA for all controls (ListBox, Edit, Button, Static, GroupBox), RegisterClassA for the window class, and a manual GetMessageA/TranslateMessage/DispatchMessageA message loop
• Custom Dark Theme -- implements a dark color scheme through WM_CTLCOLORLISTBOX, WM_CTLCOLORSTATIC, and WM_CTLCOLOREDIT message handlers, setting white text on dark backgrounds with custom HBRUSH painting
• Window Transparency -- applies WS_EX_LAYERED with SetLayeredWindowAttributes for configurable alpha transparency on the main form
• XP Visual Styles -- includes a Windows XP application manifest (XPManifest.Manifest) embedded as a Win32 resource, enabling themed common controls via comctl32.dll version 6
• Custom Icons -- ships with multiple icon sizes (32x32, 64x64) embedded as resources, applied to the form via WM_SETICON and SetClassLong
• Custom Font Rendering -- creates a "Times New Roman" font via CreateFontA and applies it to all controls with WM_SETFONT
• Centered Window Placement -- calculates screen center position using GetSystemMetrics(SM_CXSCREEN) and SM_CYSCREEN
• Refresh Capability -- "Atualizar" button clears and re-enumerates all windows on demand
• Click-to-Select -- clicking a window name in the listbox automatically fills the "current caption" field via LB_GETCURSEL and LB_GETTEXT

Technologies

Project Structure

caption-switcher/
????????? CS.dpr                        # Complete application source - window class, UI creation, message loop, window enumeration
????????? XPManifest/
???   ????????? XPManifest.Manifest       # Windows XP application manifest (Common Controls 6.0.0.0)
???   ????????? XPManifest.rc             # Resource compiler script for the manifest
????????? ConIcon/
???   ????????? ConIcon.rc                # Resource compiler script for icons (CONICON, ICO32, ICO64)
???   ????????? Icon.ico                  # Default application icon
???   ????????? Icon.png                  # Icon source image
???   ????????? 32x32.ico                 # Small icon (taskbar, title bar)
???   ????????? 64x64.ico                 # Large icon (Alt+Tab, taskbar)
????????? LICENSE                       # GNU General Public License v3.0
????????? README.md

UI Layout

The application window ("Caption Switcher v1.0", 346x324 pixels) is divided into two sections:

?????? Janelas Detectadas (Detected Windows) ???????????????????????????
???  ????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????   ???
???  ???  Sorted ListBox of visible windows       ???   ???
???  ????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????   ???
???  [ Atualizar ]                                  ???
?????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????
?????? Titulo da Janela (Window Title) ????????????????????????????????????????????????
???  Atual:  [ current caption (read-only) ]        ???
???  Novo:   [ new caption input             ]      ???
???  [ Setar ]  [ Limpar ]                          ???
?????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????
  Criado Por rios0rios0 ...

Workflow

1. Click Atualizar to populate the list with all visible windows
2. Click a window name in the list -- its current caption fills the "Atual" field
3. Type the desired new caption in the "Novo" field
4. Click Setar to apply the change
5. Click Limpar to clear both fields

Installation

1. Compile the resource files: brcc32 XPManifest\XPManifest.rc and brcc32 ConIcon\ConIcon.rc (no .res is committed, and CS.dpr links XPManifest\XPManifest.res directly)
2. Open CS.dpr in Borland Delphi 7 (or a compatible IDE)
3. Compile the project (Ctrl+F9)

Technical Details

Window Enumeration Filter

The EnumWindowsProc callback filters windows using three criteria:

1. IsWindowVisible(Wnd) -- only visible windows
2. GetWindowLong(Wnd, GWL_HWNDPARENT) = 0 or parent is the desktop -- only top-level windows
3. (GetWindowLong(Wnd, GWL_EXSTYLE) and WS_EX_TOOLWINDOW) = 0 -- excludes tool windows

Custom Color Painting

The application handles three color messages to achieve its dark theme:

• WM_CTLCOLORLISTBOX -- sets $FFFFFF text and black (0) background on the listbox
• WM_CTLCOLORSTATIC -- applies the same scheme to static labels and read-only edit controls
• WM_CTLCOLOREDIT -- applies dark styling to the editable text input

Contributing

This project is no longer actively maintained. See CONTRIBUTING.md for historical build information.

License

This project is licensed under the GNU General Public License v3.0.