# DVX GUI A DOS Visual eXecutive windowed GUI compositor for DOS, targeting DJGPP/DPMI with VESA VBE 2.0+ linear framebuffer. Motif-style beveled chrome, dirty-rectangle compositing, draggable and resizable windows, dropdown menus, scrollbars, and a declarative widget/layout system with buttons, checkboxes, radios, text inputs, dropdowns, combo boxes, sliders, spinners, progress bars, tab controls, tree views, list views, scroll panes, splitters, toolbars, status bars, images, image buttons, drawable canvases, password inputs, masked/formatted inputs, and an ANSI BBS terminal emulator. ## Building Requires the DJGPP cross-compiler (`i586-pc-msdosdjgpp-gcc`). The GUI is built as a static library (`lib/libdvx.a`). The DVX Shell (`dvxshell/`) and DXE applications (`apps/`) link against it. ``` make # builds ../lib/libdvx.a make clean # removes obj/ and lib/ ``` Set `DJGPP_PREFIX` in the Makefile if your toolchain is installed somewhere other than `~/djgpp/djgpp`. ## Architecture The library is organized in five layers. Each layer is a `.h`/`.c` pair. Application code only needs to include `dvxApp.h` (which pulls in the rest) and optionally `dvxWidget.h`. ``` Layer 1 dvxVideo VESA init, LFB mapping, backbuffer, pixel format Layer 2 dvxDraw Spans, rects, bevels, text, bitmaps (asm inner loops) Layer 3 dvxComp Dirty rectangle list, merge, LFB flush Layer 4 dvxWm Window stack, chrome, drag, resize, focus, menus, scrollbars Layer 5 dvxApp Event loop, mouse/keyboard input, public API dvxWidget Widget/layout system (optional, standalone) ``` Supporting files: | File | Purpose | |------|---------| | `dvxTypes.h` | Shared type definitions used by all layers | | `dvxFont.h` | Built-in 8x14 bitmap font glyph data | | `dvxCursor.h` | Mouse cursor bitmask data (5 shapes) | | `dvxPalette.h` | Default VGA palette for 8-bit mode | | `dvxDialog.h` | Modal dialogs (message box, file dialog) | | `dvxIcon.c` | stb_image implementation unit (BMP/PNG/JPEG/GIF) | | `dvxImageWrite.c` | stb_image_write implementation unit (PNG export) | | `thirdparty/stb_image.h` | Third-party single-header image loader | | `thirdparty/stb_image_write.h` | Third-party single-header image writer | The platform abstraction lives in `platform/`: | File | Purpose | |------|---------| | `platform/dvxPlatform.h` | OS/CPU-neutral interface: video, input, span ops, filename validation | | `platform/dvxPlatformDos.c` | DOS/DJGPP implementation: VESA, DPMI, INT 16h/33h, rep stosl/movsl | To port DVX to a new platform, implement a new `dvxPlatformXxx.c` against `platform/dvxPlatform.h` and swap it in the Makefile. No other files need modification. The widget system lives in `widgets/`: | File | Purpose | |------|---------| | `widgets/widgetInternal.h` | Shared internal header: vtable type, constants, cross-widget prototypes | | `widgets/widgetClass.c` | Widget class table: one `WidgetClassT` vtable entry per widget type | | `widgets/widgetCore.c` | Allocation, tree ops, hit testing, flag-based type queries | | `widgets/widgetLayout.c` | Two-pass layout engine (measure + arrange) | | `widgets/widgetEvent.c` | Mouse, keyboard, scroll, resize, and paint event dispatch | | `widgets/widgetOps.c` | Paint dispatcher, public operations (`wgtFind`, `wgtDestroy`, etc.) | | `widgets/widget*.c` | One file per widget type (button, checkbox, slider, etc.) | Each widget type is self-contained in its own `.c` file. Dispatch for paint, layout, mouse, keyboard, getText/setText, and destroy is driven by a per-type vtable (`WidgetClassT`) rather than switch statements in the core files. Adding a new widget type requires only a new `.c` file and an entry in the class table. --- ## Quick start ```c #include "dvxApp.h" static void onPaint(WindowT *win, RectT *dirty) { AppContextT *ctx = (AppContextT *)win->userData; const BlitOpsT *ops = dvxGetBlitOps(ctx); const DisplayT *d = dvxGetDisplay(ctx); uint32_t blue = packColor(d, 0, 0, 200); for (int32_t y = 0; y < win->contentH; y++) { ops->spanFill(win->contentBuf + y * win->contentPitch, blue, win->contentW); } } int main(void) { AppContextT ctx; if (dvxInit(&ctx, 1024, 768, 16) != 0) { return 1; } WindowT *win = dvxCreateWindow(&ctx, "Hello", 100, 100, 300, 200, true); win->userData = &ctx; win->onPaint = onPaint; RectT r = {0, 0, win->contentW, win->contentH}; win->onPaint(win, &r); dvxRun(&ctx); dvxShutdown(&ctx); return 0; } ``` ## Quick start (widgets) ```c #include "dvxApp.h" #include "dvxWidget.h" static void onButtonClick(WidgetT *w) { WidgetT *root = w; while (root->parent) root = root->parent; WidgetT *lbl = wgtFind(root, "status"); if (lbl) { wgtSetText(lbl, "Clicked!"); wgtInvalidate(lbl); } } int main(void) { AppContextT ctx; dvxInit(&ctx, 1024, 768, 16); WindowT *win = dvxCreateWindow(&ctx, "Widgets", 100, 100, 260, 200, true); win->userData = &ctx; WidgetT *root = wgtInitWindow(&ctx, win); WidgetT *lbl = wgtLabel(root, "Ready."); wgtSetName(lbl, "status"); wgtHSeparator(root); WidgetT *row = wgtHBox(root); wgtLabel(row, "Name:"); wgtTextInput(row, 64); WidgetT *btn = wgtButton(root, "Go"); btn->onClick = onButtonClick; wgtInvalidate(root); // initial layout + paint dvxRun(&ctx); dvxShutdown(&ctx); return 0; } ``` --- ## Application API (`dvxApp.h`) ### Lifecycle ```c int32_t dvxInit(AppContextT *ctx, int32_t requestedW, int32_t requestedH, int32_t preferredBpp); ``` Initialize VESA video, input, fonts, color scheme, and cursors. Finds a mode matching the requested resolution and bit depth (8, 15, 16, or 32). Returns 0 on success, -1 on failure. ```c void dvxRun(AppContextT *ctx); ``` Enter the main event loop. Handles mouse movement, button clicks, keyboard input, window management, dirty-rectangle compositing, and LFB flush. Returns when `dvxQuit()` is called or ESC is pressed. ```c bool dvxUpdate(AppContextT *ctx); ``` Process one iteration of the event loop: poll input, dispatch events, composite dirty regions, and flush. Returns `true` if the GUI is still running, `false` when exit has been requested. Use this instead of `dvxRun()` when embedding the GUI inside an existing main loop. ```c void dvxShutdown(AppContextT *ctx); ``` Restore text mode, release LFB mapping, and free the backbuffer. ```c void dvxQuit(AppContextT *ctx); ``` Request exit from the main loop. `dvxRun()` returns on the next iteration. ### Windows ```c WindowT *dvxCreateWindow(AppContextT *ctx, const char *title, int32_t x, int32_t y, int32_t w, int32_t h, bool resizable); ``` Create a window at screen position (`x`, `y`) with outer dimensions `w` x `h`. If `resizable` is true, the window gets resize handles and a maximize button. The window is raised to the top and given focus. Returns NULL on failure. After creation, set `win->userData` and install callbacks: | Callback | Signature | When called | |----------|-----------|-------------| | `onPaint` | `void (WindowT *win, RectT *dirtyArea)` | Content needs redrawing | | `onKey` | `void (WindowT *win, int32_t key, int32_t mod)` | Key press (focused window) | | `onMouse` | `void (WindowT *win, int32_t x, int32_t y, int32_t buttons)` | Mouse event in content area | | `onResize` | `void (WindowT *win, int32_t newW, int32_t newH)` | Window resized | | `onClose` | `void (WindowT *win)` | Close button double-clicked | | `onMenu` | `void (WindowT *win, int32_t menuId)` | Menu item selected | | `onScroll` | `void (WindowT *win, ScrollbarOrientE orient, int32_t value)` | Scrollbar moved | Mouse/key coordinates are relative to the content area. `buttons` is a bitmask (bit 0 = left, bit 1 = right, bit 2 = middle). Example: ```c static void onClose(WindowT *win) { AppContextT *ctx = (AppContextT *)win->userData; dvxDestroyWindow(ctx, win); } WindowT *win = dvxCreateWindow(&ctx, "My Window", 50, 50, 400, 300, true); win->userData = &ctx; win->onClose = onClose; win->onPaint = myPaintHandler; win->onMenu = myMenuHandler; ``` ```c void dvxDestroyWindow(AppContextT *ctx, WindowT *win); ``` Remove a window from the stack and free its resources. ```c void dvxSetTitle(AppContextT *ctx, WindowT *win, const char *title); ``` Change the title bar text. ```c int32_t dvxSetWindowIcon(AppContextT *ctx, WindowT *win, const char *path); ``` Load a BMP, PNG, JPEG, or GIF image and assign it as the window's minimized icon. The image is converted to the display pixel format and scaled to 64x64. Returns 0 on success. ```c void dvxMinimizeWindow(AppContextT *ctx, WindowT *win); void dvxMaximizeWindow(AppContextT *ctx, WindowT *win); void dvxFitWindow(AppContextT *ctx, WindowT *win); ``` `dvxFitWindow` resizes the window to fit its widget tree's natural size. ### Window arrangement ```c dvxCascadeWindows(&ctx); // staggered cascade dvxTileWindows(&ctx); // grid tile dvxTileWindowsH(&ctx); // side-by-side dvxTileWindowsV(&ctx); // top-to-bottom ``` ### Invalidation ```c void dvxInvalidateRect(AppContextT *ctx, WindowT *win, int32_t x, int32_t y, int32_t w, int32_t h); void dvxInvalidateWindow(AppContextT *ctx, WindowT *win); ``` Mark a region (or the entire content area) as needing repaint. The compositor flushes dirty rectangles to the LFB on the next frame. ### Clipboard ```c dvxClipboardCopy("Hello", 5); int32_t len; const char *text = dvxClipboardGet(&len); ``` ### Screenshots ```c dvxScreenshot(&ctx, "screen.png"); // entire screen dvxWindowScreenshot(&ctx, win, "window.png"); // single window content ``` ### Accessors ```c DisplayT *dvxGetDisplay(AppContextT *ctx); const BlitOpsT *dvxGetBlitOps(const AppContextT *ctx); const BitmapFontT *dvxGetFont(const AppContextT *ctx); const ColorSchemeT *dvxGetColors(const AppContextT *ctx); ``` ### Window properties Set these directly on the `WindowT` struct after creation: | Field | Type | Default | Description | |-------|------|---------|-------------| | `maxW` | `int32_t` | -1 | Maximum width when maximized (-1 = screen width) | | `maxH` | `int32_t` | -1 | Maximum height when maximized (-1 = screen height) | | `userData` | `void *` | NULL | Application data pointer, passed through to callbacks | ### Content buffer Each window has a persistent content backbuffer: | Field | Description | |-------|-------------| | `contentBuf` | Pixel data in display format | | `contentPitch` | Bytes per scanline | | `contentW` | Width in pixels | | `contentH` | Height in pixels | Paint callbacks write directly into `contentBuf`. The compositor copies visible portions to the screen backbuffer, then flushes dirty rects to the LFB. --- ## Menu bars ```c WindowT *win = dvxCreateWindow(&ctx, "Menus", 50, 50, 400, 300, true); win->onMenu = onMenuCb; MenuBarT *bar = wmAddMenuBar(win); MenuT *fileMenu = wmAddMenu(bar, "&File"); wmAddMenuItem(fileMenu, "&New", CMD_FILE_NEW); wmAddMenuItem(fileMenu, "&Open...", CMD_FILE_OPEN); wmAddMenuItem(fileMenu, "&Save", CMD_FILE_SAVE); wmAddMenuSeparator(fileMenu); wmAddMenuItem(fileMenu, "E&xit", CMD_FILE_EXIT); MenuT *viewMenu = wmAddMenu(bar, "&View"); wmAddMenuCheckItem(viewMenu, "Tool&bar", CMD_VIEW_TOOLBAR, true); wmAddMenuCheckItem(viewMenu, "&Status Bar", CMD_VIEW_STATUSBAR, true); wmAddMenuSeparator(viewMenu); wmAddMenuRadioItem(viewMenu, "S&mall", CMD_VIEW_SIZE_SMALL, false); wmAddMenuRadioItem(viewMenu, "Me&dium", CMD_VIEW_SIZE_MED, true); wmAddMenuRadioItem(viewMenu, "&Large", CMD_VIEW_SIZE_LARGE, false); // Cascading submenu MenuT *zoomMenu = wmAddSubMenu(viewMenu, "&Zoom"); wmAddMenuItem(zoomMenu, "Zoom &In", CMD_ZOOM_IN); wmAddMenuItem(zoomMenu, "Zoom &Out", CMD_ZOOM_OUT); wmUpdateContentRect(win); wmReallocContentBuf(win, &ctx.display); ``` The `&` prefix marks accelerator keys -- Alt+F opens "&File". Up to 8 menus per bar, 16 items per menu, submenus nested up to 4 deep. Menu callback: ```c static void onMenuCb(WindowT *win, int32_t menuId) { AppContextT *ctx = (AppContextT *)win->userData; switch (menuId) { case CMD_FILE_EXIT: dvxQuit(ctx); break; } } ``` ### Context menus Right-click menus can be attached to any window or widget: ```c // Window-level context menu MenuT *ctxMenu = wmCreateMenu(); wmAddMenuItem(ctxMenu, "Cu&t", CMD_CUT); wmAddMenuItem(ctxMenu, "&Copy", CMD_COPY); wmAddMenuItem(ctxMenu, "&Paste", CMD_PASTE); wmAddMenuSeparator(ctxMenu); wmAddMenuItem(ctxMenu, "&Properties...", CMD_PROPS); win->contextMenu = ctxMenu; // Widget-level context menu WidgetT *lb = wgtListBox(root); MenuT *lbCtx = wmCreateMenu(); wmAddMenuItem(lbCtx, "&Delete", CMD_DELETE); wmAddMenuItem(lbCtx, "Select &All", CMD_SELALL); lb->contextMenu = lbCtx; ``` Context menus route through the window's `onMenu` callback. The caller owns the `MenuT` (not freed by the widget system). --- ## Accelerator tables Global hotkeys routed through the window's `onMenu` callback: ```c AccelTableT *accel = dvxCreateAccelTable(); dvxAddAccel(accel, 'N', ACCEL_CTRL, CMD_FILE_NEW); dvxAddAccel(accel, 'O', ACCEL_CTRL, CMD_FILE_OPEN); dvxAddAccel(accel, 'S', ACCEL_CTRL, CMD_FILE_SAVE); dvxAddAccel(accel, 'Q', ACCEL_CTRL, CMD_FILE_EXIT); dvxAddAccel(accel, KEY_F1, 0, CMD_HELP_ABOUT); win->accelTable = accel; ``` Modifier constants: `ACCEL_SHIFT` (0x03), `ACCEL_CTRL` (0x04), `ACCEL_ALT` (0x08). Key constants for extended keys: `KEY_F1`--`KEY_F12`, `KEY_INSERT`, `KEY_DELETE`, `KEY_HOME`, `KEY_END`, `KEY_PGUP`, `KEY_PGDN`. Up to 32 entries per table. The table is freed with `dvxFreeAccelTable()`. --- ## Scrollbars ```c wmAddVScrollbar(win, 0, 100, 25); // vertical, range 0-100, page size 25 wmAddHScrollbar(win, 0, 100, 25); // horizontal wmUpdateContentRect(win); wmReallocContentBuf(win, &ctx.display); ``` The `onScroll` callback fires when the user drags the thumb or clicks the arrow buttons / trough. Widget windows manage their own scrollbars automatically -- do not add them manually. --- ## Dialogs (`dvxDialog.h`) ### Message box ```c int32_t result = dvxMessageBox(&ctx, "Confirm", "Are you sure you want to exit?", MB_YESNO | MB_ICONQUESTION); if (result == ID_YES) { dvxQuit(&ctx); } ``` Button flags: `MB_OK`, `MB_OKCANCEL`, `MB_YESNO`, `MB_YESNOCANCEL`, `MB_RETRYCANCEL`. Icon flags: `MB_ICONINFO`, `MB_ICONWARNING`, `MB_ICONERROR`, `MB_ICONQUESTION`. Return values: `ID_OK`, `ID_CANCEL`, `ID_YES`, `ID_NO`, `ID_RETRY`. ### File dialog ```c static const FileFilterT filters[] = { {"All Files (*.*)", "*.*"}, {"Text Files (*.txt)", "*.txt"}, {"Bitmap Files (*.bmp)", "*.bmp"} }; char path[260]; if (dvxFileDialog(&ctx, "Open File", FD_OPEN, NULL, filters, 3, path, sizeof(path))) { // path contains the selected filename } if (dvxFileDialog(&ctx, "Save As", FD_SAVE, NULL, filters, 3, path, sizeof(path))) { // path contains the chosen filename } ``` Flags: `FD_OPEN`, `FD_SAVE`. Pass `NULL` for `initialDir` to use the current directory. Filename validation is platform-specific (DOS 8.3 on the DOS platform). --- ## Video and drawing (`dvxVideo.h`, `dvxDraw.h`) These are lower-level APIs. Application code typically only needs `packColor`. ```c uint32_t packColor(const DisplayT *d, uint8_t r, uint8_t g, uint8_t b); ``` Pack an RGB triple into the display's pixel format. ```c void rectFill(DisplayT *d, const BlitOpsT *ops, int32_t x, int32_t y, int32_t w, int32_t h, uint32_t color); ``` Fill a rectangle with a solid color (clipped to the display clip rect). ```c void drawBevel(DisplayT *d, const BlitOpsT *ops, int32_t x, int32_t y, int32_t w, int32_t h, const BevelStyleT *style); ``` Draw a beveled frame. `BevelStyleT` specifies highlight, shadow, face colors and border width. ```c void drawText(DisplayT *d, const BlitOpsT *ops, const BitmapFontT *font, int32_t x, int32_t y, const char *text, uint32_t fg, uint32_t bg, bool opaque); int32_t drawChar(DisplayT *d, const BlitOpsT *ops, const BitmapFontT *font, int32_t x, int32_t y, char ch, uint32_t fg, uint32_t bg, bool opaque); int32_t textWidth(const BitmapFontT *font, const char *text); ``` Draw text using the built-in 8-pixel-wide bitmap font. `opaque` controls whether background pixels are drawn. `drawChar` returns the advance width. ```c void drawTextN(DisplayT *d, const BlitOpsT *ops, const BitmapFontT *font, int32_t x, int32_t y, const char *text, int32_t count, uint32_t fg, uint32_t bg, bool opaque); ``` Bulk-render exactly `count` characters. Much faster than calling `drawChar` per character because clip bounds are computed once and background is filled in bulk. ```c void drawTermRow(DisplayT *d, const BlitOpsT *ops, const BitmapFontT *font, int32_t x, int32_t y, int32_t cols, const uint8_t *lineData, const uint32_t *palette, bool blinkVisible, int32_t cursorCol); ``` Bulk-render a row of terminal character cells. `lineData` points to `(char, attr)` byte pairs (2 bytes per cell). `palette` is a 16-entry packed-color table. `blinkVisible` controls blink attribute visibility. `cursorCol` is the column to draw inverted (-1 for no cursor). This is much faster than calling `drawChar` per cell because clip bounds are computed once for the whole row and there is no per-character function call overhead. ```c char accelParse(const char *text); ``` Parse an accelerator key from text with `&` markers (e.g. `"E&xit"` returns `'x'`). Returns the lowercase accelerator character, or 0 if none found. ```c void drawTextAccel(DisplayT *d, const BlitOpsT *ops, const BitmapFontT *font, int32_t x, int32_t y, const char *text, uint32_t fg, uint32_t bg, bool opaque); int32_t textWidthAccel(const BitmapFontT *font, const char *text); ``` Draw/measure text with `&` accelerator processing. The character after `&` is underlined. `&&` produces a literal `&`. `textWidthAccel` returns the width in pixels, excluding `&` markers. ```c void drawFocusRect(DisplayT *d, const BlitOpsT *ops, int32_t x, int32_t y, int32_t w, int32_t h, uint32_t color); ``` Draw a dotted rectangle outline (every other pixel). Used to indicate keyboard focus on widgets. ```c void drawMaskedBitmap(DisplayT *d, const BlitOpsT *ops, int32_t x, int32_t y, int32_t w, int32_t h, const uint16_t *andMask, const uint16_t *xorData, uint32_t fgColor, uint32_t bgColor); ``` Draw a 1-bit bitmap with AND/XOR masks (used for mouse cursors). Each row is a `uint16_t`. Pixels where the AND mask is 0 are drawn using the XOR data to select `fgColor` or `bgColor`. ```c void drawHLine(DisplayT *d, const BlitOpsT *ops, int32_t x, int32_t y, int32_t w, uint32_t color); void drawVLine(DisplayT *d, const BlitOpsT *ops, int32_t x, int32_t y, int32_t h, uint32_t color); ``` ```c void rectCopy(DisplayT *d, const BlitOpsT *ops, int32_t dstX, int32_t dstY, const uint8_t *srcBuf, int32_t srcPitch, int32_t srcX, int32_t srcY, int32_t w, int32_t h); ``` Blit from a source buffer to the backbuffer with clipping. ```c void setClipRect(DisplayT *d, int32_t x, int32_t y, int32_t w, int32_t h); void resetClipRect(DisplayT *d); ``` --- ## Widget system (`dvxWidget.h`) An optional declarative layout system inspired by Amiga MUI and PC GEOS. Widgets are arranged in a tree of VBox/HBox containers. A two-pass layout engine (measure minimum sizes, then distribute space) handles geometry automatically. Scrollbars appear when the window is too small for the content. ### Initialization ```c WidgetT *wgtInitWindow(AppContextT *ctx, WindowT *win); ``` Attach the widget system to a window. Returns the root container (a VBox filling the content area). Installs `onPaint`, `onMouse`, `onKey`, and `onResize` handlers on the window. Build the widget tree by passing the returned root (or its children) as `parent` to the widget creation functions below. Call `wgtInvalidate(root)` after the tree is fully built to trigger the initial layout and paint. ### Containers ```c WidgetT *wgtVBox(WidgetT *parent); // vertical stack WidgetT *wgtHBox(WidgetT *parent); // horizontal stack WidgetT *wgtFrame(WidgetT *parent, const char *title); // titled border ``` Containers hold child widgets and control layout direction. `wgtFrame` draws a styled border with a title label and lays out children vertically. Example: ```c WidgetT *root = wgtInitWindow(&ctx, win); WidgetT *frame = wgtFrame(root, "User Input"); WidgetT *row1 = wgtHBox(frame); wgtLabel(row1, "Name:"); wgtTextInput(row1, 64); WidgetT *row2 = wgtHBox(frame); wgtLabel(row2, "Email:"); wgtTextInput(row2, 128); WidgetT *btnRow = wgtHBox(root); btnRow->align = AlignEndE; wgtButton(btnRow, "OK"); wgtButton(btnRow, "Cancel"); wgtInvalidate(root); ``` Frame styles (set `w->as.frame.style` after creation): | Style | Description | |-------|-------------| | `FrameInE` | Beveled inward / sunken (default) | | `FrameOutE` | Beveled outward / raised | | `FrameFlatE` | Solid color line; set `w->as.frame.color` (0 = windowShadow) | Container properties (set directly on the returned `WidgetT *`): | Field | Type | Default | Description | |-------|------|---------|-------------| | `align` | `WidgetAlignE` | `AlignStartE` | Main-axis alignment when no children have weight | | `spacing` | `int32_t` | 0 (4px) | Tagged size: gap between children | | `padding` | `int32_t` | 0 (4px) | Tagged size: internal padding | Alignment values: | Value | HBox meaning | VBox meaning | |-------|-------------|-------------| | `AlignStartE` | left | top | | `AlignCenterE` | center | center | | `AlignEndE` | right | bottom | ### Label ```c WidgetT *wgtLabel(WidgetT *parent, const char *text); ``` Static text label. Sized to fit its text. Supports `&` accelerator markers. ```c WidgetT *lbl = wgtLabel(root, "&Status:"); wgtSetText(lbl, "Connected"); // change text later ``` ### Button ```c WidgetT *wgtButton(WidgetT *parent, const char *text); ``` Beveled push button. Visually depresses on mouse-down, tracks the cursor while held, fires `onClick` on release if still over the button. ```c static void onOkClick(WidgetT *w) { // handle button press } WidgetT *btn = wgtButton(root, "&OK"); btn->onClick = onOkClick; ``` ### Checkbox ```c WidgetT *wgtCheckbox(WidgetT *parent, const char *text); ``` Toggle checkbox. Read/write `w->as.checkbox.checked`. ```c WidgetT *chk = wgtCheckbox(root, "Enable feature &A"); chk->as.checkbox.checked = true; // pre-check chk->onChange = onCheckChanged; // notified on toggle ``` ### Radio buttons ```c WidgetT *wgtRadioGroup(WidgetT *parent); WidgetT *wgtRadio(WidgetT *parent, const char *text); ``` Radio buttons with diamond-shaped indicators. Create a group, then add options as children. The group tracks the selected index. ```c WidgetT *rg = wgtRadioGroup(root); wgtRadio(rg, "Option &1"); wgtRadio(rg, "Option &2"); wgtRadio(rg, "Option &3"); rg->onChange = onRadioChanged; // Read selection: int32_t idx = rg->as.radioGroup.selectedIdx; ``` ### TextInput ```c WidgetT *wgtTextInput(WidgetT *parent, int32_t maxLen); ``` Single-line text input field. `maxLen` is the buffer capacity. Default weight is 100 (stretches to fill). ```c WidgetT *row = wgtHBox(root); wgtLabel(row, "&Name:"); WidgetT *input = wgtTextInput(row, 64); wgtSetText(input, "Default text"); input->onChange = onTextChanged; // Read text: const char *text = wgtGetText(input); ``` Editing features: cursor movement (arrows, Home, End), insert/overwrite, selection (Shift+arrows, Shift+Home/End, Ctrl+A, double-click word, triple-click all), clipboard (Ctrl+C copy, Ctrl+V paste, Ctrl+X cut), single-level undo (Ctrl+Z), and horizontal scrolling when text exceeds the visible width. ### PasswordInput ```c WidgetT *wgtPasswordInput(WidgetT *parent, int32_t maxLen); ``` Identical to `wgtTextInput` except characters are displayed as bullets. Copy and cut to clipboard are disabled; paste is allowed. ```c WidgetT *pw = wgtPasswordInput(root, 32); ``` ### MaskedInput ```c WidgetT *wgtMaskedInput(WidgetT *parent, const char *mask); ``` Formatted input field. Mask characters: `#` = digit, `A` = letter, `*` = any printable. All other characters are fixed literals. ```c wgtMaskedInput(root, "(###) ###-####"); // US phone wgtMaskedInput(root, "##/##/####"); // date wgtMaskedInput(root, "###-##-####"); // SSN ``` The mask string must remain valid for the widget's lifetime. ### TextArea ```c WidgetT *wgtTextArea(WidgetT *parent, int32_t maxLen); ``` Multi-line text editor with vertical and horizontal scrollbars. ```c WidgetT *ta = wgtTextArea(root, 4096); ta->weight = 100; wgtSetText(ta, "Line 1\nLine 2\nLine 3"); ``` Supports all TextInput editing features plus multi-line selection, Enter for newlines, and vertical/horizontal auto-scroll. ### ListBox ```c WidgetT *wgtListBox(WidgetT *parent); void wgtListBoxSetItems(WidgetT *w, const char **items, int32_t count); int32_t wgtListBoxGetSelected(const WidgetT *w); void wgtListBoxSetSelected(WidgetT *w, int32_t idx); ``` ```c static const char *items[] = {"Alpha", "Beta", "Gamma", "Delta"}; WidgetT *lb = wgtListBox(root); wgtListBoxSetItems(lb, items, 4); wgtListBoxSetSelected(lb, 0); lb->weight = 100; lb->onClick = onItemSelected; ``` Multi-select mode: ```c wgtListBoxSetMultiSelect(lb, true); wgtListBoxSetItemSelected(lb, 0, true); wgtListBoxSetItemSelected(lb, 2, true); bool sel = wgtListBoxIsItemSelected(lb, 1); wgtListBoxSelectAll(lb); wgtListBoxClearSelection(lb); ``` Reorderable (drag-and-drop items): ```c wgtListBoxSetReorderable(lb, true); ``` ### Dropdown ```c WidgetT *wgtDropdown(WidgetT *parent); void wgtDropdownSetItems(WidgetT *w, const char **items, int32_t count); int32_t wgtDropdownGetSelected(const WidgetT *w); void wgtDropdownSetSelected(WidgetT *w, int32_t idx); ``` Non-editable selection widget with a popup list. ```c static const char *colors[] = {"Red", "Green", "Blue", "Yellow"}; WidgetT *dd = wgtDropdown(root); wgtDropdownSetItems(dd, colors, 4); wgtDropdownSetSelected(dd, 0); dd->onChange = onColorChanged; ``` The items array must remain valid for the widget's lifetime. ### ComboBox ```c WidgetT *wgtComboBox(WidgetT *parent, int32_t maxLen); void wgtComboBoxSetItems(WidgetT *w, const char **items, int32_t count); int32_t wgtComboBoxGetSelected(const WidgetT *w); void wgtComboBoxSetSelected(WidgetT *w, int32_t idx); ``` Editable text field with a dropdown list. ```c static const char *sizes[] = {"Small", "Medium", "Large", "Extra Large"}; WidgetT *cb = wgtComboBox(root, 32); wgtComboBoxSetItems(cb, sizes, 4); wgtComboBoxSetSelected(cb, 1); cb->onChange = onSizeChanged; // Read typed/selected text: const char *text = wgtGetText(cb); ``` ### ProgressBar ```c WidgetT *wgtProgressBar(WidgetT *parent); // horizontal WidgetT *wgtProgressBarV(WidgetT *parent); // vertical void wgtProgressBarSetValue(WidgetT *w, int32_t value); int32_t wgtProgressBarGetValue(const WidgetT *w); ``` ```c WidgetT *pb = wgtProgressBar(root); pb->weight = 100; wgtProgressBarSetValue(pb, 65); WidgetT *pbV = wgtProgressBarV(root); wgtProgressBarSetValue(pbV, 75); ``` Value is 0--100 (percentage). ### Slider ```c WidgetT *wgtSlider(WidgetT *parent, int32_t minVal, int32_t maxVal); void wgtSliderSetValue(WidgetT *w, int32_t value); int32_t wgtSliderGetValue(const WidgetT *w); ``` ```c WidgetT *slider = wgtSlider(root, 0, 100); wgtSliderSetValue(slider, 50); slider->onChange = onVolumeChanged; // Vertical slider: WidgetT *vSlider = wgtSlider(root, 0, 255); vSlider->as.slider.vertical = true; ``` ### Spinner ```c WidgetT *wgtSpinner(WidgetT *parent, int32_t minVal, int32_t maxVal, int32_t step); void wgtSpinnerSetValue(WidgetT *w, int32_t value); int32_t wgtSpinnerGetValue(const WidgetT *w); void wgtSpinnerSetRange(WidgetT *w, int32_t minVal, int32_t maxVal); void wgtSpinnerSetStep(WidgetT *w, int32_t step); ``` Numeric up/down input with increment/decrement buttons. ```c WidgetT *spin = wgtSpinner(root, 0, 999, 1); wgtSpinnerSetValue(spin, 42); spin->weight = 50; spin->onChange = onQuantityChanged; ``` Up/Down arrows increment/decrement by `step`; Page Up/Down by `step * 10`. Enter commits the typed value; Escape reverts. ### TabControl ```c WidgetT *wgtTabControl(WidgetT *parent); WidgetT *wgtTabPage(WidgetT *parent, const char *title); void wgtTabControlSetActive(WidgetT *w, int32_t idx); int32_t wgtTabControlGetActive(const WidgetT *w); ``` ```c WidgetT *tabs = wgtTabControl(root); WidgetT *page1 = wgtTabPage(tabs, "&General"); wgtLabel(page1, "General settings"); wgtCheckbox(page1, "&Enable logging"); WidgetT *page2 = wgtTabPage(tabs, "&Advanced"); wgtLabel(page2, "Advanced settings"); WidgetT *slider = wgtSlider(page2, 0, 100); wgtSliderSetValue(slider, 75); WidgetT *page3 = wgtTabPage(tabs, "A&bout"); wgtLabel(page3, "Version 1.0"); ``` Each page is a VBox. Only the active page is visible and receives layout. ### StatusBar ```c WidgetT *wgtStatusBar(WidgetT *parent); ``` Horizontal container with sunken panel background. Place at the bottom of the root VBox. ```c WidgetT *sb = wgtStatusBar(root); WidgetT *msg = wgtLabel(sb, "Ready"); msg->weight = 100; // stretch to fill wgtLabel(sb, "Line 1, Col 1"); ``` ### Toolbar ```c WidgetT *wgtToolbar(WidgetT *parent); ``` Horizontal container with raised background. Place at the top of the root VBox. ```c WidgetT *tb = wgtToolbar(root); WidgetT *btnNew = wgtImageButton(tb, newPixels, 16, 16, 16 * bpp); WidgetT *btnOpen = wgtImageButton(tb, openPixels, 16, 16, 16 * bpp); WidgetT *btnSave = wgtImageButton(tb, savePixels, 16, 16, 16 * bpp); wgtVSeparator(tb); wgtButton(tb, "&Help"); ``` ### TreeView ```c WidgetT *wgtTreeView(WidgetT *parent); WidgetT *wgtTreeItem(WidgetT *parent, const char *text); void wgtTreeItemSetExpanded(WidgetT *w, bool expanded); bool wgtTreeItemIsExpanded(const WidgetT *w); WidgetT *wgtTreeViewGetSelected(const WidgetT *w); void wgtTreeViewSetSelected(WidgetT *w, WidgetT *item); ``` ```c WidgetT *tree = wgtTreeView(root); WidgetT *docs = wgtTreeItem(tree, "Documents"); wgtTreeItemSetExpanded(docs, true); wgtTreeItem(docs, "README.md"); wgtTreeItem(docs, "DESIGN.md"); WidgetT *src = wgtTreeItem(docs, "src"); wgtTreeItemSetExpanded(src, true); wgtTreeItem(src, "main.c"); wgtTreeItem(src, "utils.c"); WidgetT *images = wgtTreeItem(tree, "Images"); wgtTreeItem(images, "logo.png"); wgtTreeItem(images, "icon.bmp"); ``` Multi-select and reorderable: ```c wgtTreeViewSetMultiSelect(tree, true); wgtTreeViewSetReorderable(tree, true); ``` The tree view manages its own scrollbars automatically. Default weight is 100. ### ListView ```c WidgetT *wgtListView(WidgetT *parent); void wgtListViewSetColumns(WidgetT *w, const ListViewColT *cols, int32_t count); void wgtListViewSetData(WidgetT *w, const char **cellData, int32_t rowCount); int32_t wgtListViewGetSelected(const WidgetT *w); void wgtListViewSetSelected(WidgetT *w, int32_t idx); ``` Multi-column list with sortable headers and resizable columns. ```c static const ListViewColT cols[] = { {"Name", wgtChars(16), ListViewAlignLeftE}, {"Size", wgtChars(8), ListViewAlignRightE}, {"Type", wgtChars(12), ListViewAlignLeftE}, {"Modified", wgtChars(12), ListViewAlignLeftE} }; static const char *data[] = { "AUTOEXEC.BAT", "412", "Batch File", "03/15/1994", "CONFIG.SYS", "256", "System File", "03/15/1994", "COMMAND.COM", "54,645", "Application", "09/30/1993", }; WidgetT *lv = wgtListView(root); wgtListViewSetColumns(lv, cols, 4); wgtListViewSetData(lv, data, 3); wgtListViewSetSelected(lv, 0); lv->weight = 100; ``` Multi-select and sorting: ```c wgtListViewSetMultiSelect(lv, true); wgtListViewSetSort(lv, 0, ListViewSortAscE); wgtListViewSetReorderable(lv, true); // Header click callback for custom sort logic: wgtListViewSetHeaderClickCallback(lv, onHeaderClick); ``` Column widths support tagged sizes (`wgtPixels`, `wgtChars`, `wgtPercent`). Cell data is a flat array of strings in row-major order. Both the column and data arrays must remain valid for the widget's lifetime. ### ScrollPane ```c WidgetT *wgtScrollPane(WidgetT *parent); ``` Scrollable container. Children are laid out vertically at their natural size. Scrollbars appear automatically when content exceeds the visible area. ```c WidgetT *sp = wgtScrollPane(root); sp->weight = 100; sp->padding = wgtPixels(4); sp->spacing = wgtPixels(4); wgtLabel(sp, "Scrollable content:"); wgtHSeparator(sp); for (int32_t i = 0; i < 8; i++) { wgtCheckbox(sp, items[i]); } wgtHSeparator(sp); wgtButton(sp, "Scrolled Button"); ``` ### Splitter ```c WidgetT *wgtSplitter(WidgetT *parent, bool vertical); void wgtSplitterSetPos(WidgetT *w, int32_t pos); int32_t wgtSplitterGetPos(const WidgetT *w); ``` Resizable divider between exactly two child widgets. `vertical = true` creates a left|right split; `false` creates a top/bottom split. ```c // Horizontal split: tree on left, list on right WidgetT *vSplit = wgtSplitter(root, true); vSplit->weight = 100; wgtSplitterSetPos(vSplit, 150); WidgetT *leftTree = wgtTreeView(vSplit); // ... populate tree ... WidgetT *rightList = wgtListBox(vSplit); // ... populate list ... ``` Nested splitters for complex layouts: ```c // Outer: top/bottom split WidgetT *hSplit = wgtSplitter(root, false); hSplit->weight = 100; wgtSplitterSetPos(hSplit, 120); // Top pane: left/right split WidgetT *vSplit = wgtSplitter(hSplit, true); wgtSplitterSetPos(vSplit, 120); wgtTreeView(vSplit); // left wgtListBox(vSplit); // right // Bottom pane: detail view WidgetT *detail = wgtFrame(hSplit, "Preview"); wgtLabel(detail, "Select a file above."); ``` ### Image ```c WidgetT *wgtImage(WidgetT *parent, uint8_t *data, int32_t w, int32_t h, int32_t pitch); WidgetT *wgtImageFromFile(WidgetT *parent, const char *path); void wgtImageSetData(WidgetT *w, uint8_t *data, int32_t imgW, int32_t imgH, int32_t pitch); ``` ```c // From file (BMP, PNG, JPEG, GIF): wgtImageFromFile(root, "sample.bmp"); // From pixel buffer (display format, takes ownership): uint8_t *pixels = loadMyImage(&w, &h, &pitch); wgtImage(root, pixels, w, h, pitch); ``` ### ImageButton ```c WidgetT *wgtImageButton(WidgetT *parent, uint8_t *data, int32_t w, int32_t h, int32_t pitch); void wgtImageButtonSetData(WidgetT *w, uint8_t *data, int32_t imgW, int32_t imgH, int32_t pitch); ``` Push button that displays an image instead of text. Behaves identically to `wgtButton`. ```c uint8_t *iconData = loadBmpPixels(&ctx, "new.bmp", &imgW, &imgH, &imgPitch); WidgetT *btn = wgtImageButton(tb, iconData, imgW, imgH, imgPitch); btn->onClick = onNewClick; ``` Takes ownership of the pixel buffer (freed on destroy). ### Canvas ```c WidgetT *wgtCanvas(WidgetT *parent, int32_t w, int32_t h); ``` Drawable bitmap canvas with a sunken bevel border. Supports interactive freehand drawing (mouse strokes) and programmatic drawing. ```c const DisplayT *d = dvxGetDisplay(&ctx); WidgetT *cv = wgtCanvas(root, 280, 100); wgtCanvasClear(cv, packColor(d, 255, 255, 255)); wgtCanvasSetPenColor(cv, packColor(d, 200, 0, 0)); wgtCanvasDrawRect(cv, 5, 5, 50, 35); wgtCanvasSetPenColor(cv, packColor(d, 0, 0, 200)); wgtCanvasFillCircle(cv, 150, 50, 25); wgtCanvasSetPenColor(cv, packColor(d, 0, 150, 0)); wgtCanvasSetPenSize(cv, 3); wgtCanvasDrawLine(cv, 70, 5, 130, 90); // Individual pixels: wgtCanvasSetPixel(cv, 10, 10, packColor(d, 255, 0, 0)); uint32_t px = wgtCanvasGetPixel(cv, 10, 10); // Save/load: wgtCanvasSave(cv, "drawing.png"); wgtCanvasLoad(cv, "image.png"); ``` Drawing primitives: `wgtCanvasDrawLine`, `wgtCanvasDrawRect` (outline), `wgtCanvasFillRect` (solid), `wgtCanvasFillCircle`. All use the current pen color and clip to the canvas bounds. ### ANSI Terminal ```c WidgetT *wgtAnsiTerm(WidgetT *parent, int32_t cols, int32_t rows); ``` ANSI BBS terminal emulator. Displays a character grid (default 80x25 if cols/rows are 0) with full ANSI escape sequence support and a 16-color CGA palette. ```c WidgetT *term = wgtAnsiTerm(root, 80, 25); term->weight = 100; wgtAnsiTermSetScrollback(term, 500); // Feed ANSI content directly: static const uint8_t ansiData[] = "\x1B[2J" // clear screen "\x1B[1;34m=== Welcome ===\x1B[0m\r\n" "\x1B[1mBold\x1B[0m, " "\x1B[7mReverse\x1B[0m, " "\x1B[5mBlinking\x1B[0m\r\n" "\x1B[31m Red \x1B[32m Green \x1B[34m Blue \x1B[0m\r\n"; wgtAnsiTermWrite(term, ansiData, sizeof(ansiData) - 1); ``` Connect to a communications interface: ```c static int32_t myRead(void *ctx, uint8_t *buf, int32_t maxLen) { return serialRead((SerialT *)ctx, buf, maxLen); } static int32_t myWrite(void *ctx, const uint8_t *buf, int32_t len) { return serialWrite((SerialT *)ctx, buf, len); } wgtAnsiTermSetComm(term, &serial, myRead, myWrite); ``` ANSI escape sequences supported: | Sequence | Description | |----------|-------------| | `ESC[H` / `ESC[f` | Cursor position (CUP/HVP) | | `ESC[A/B/C/D` | Cursor up/down/forward/back | | `ESC[J` | Erase display (0=to end, 1=to start, 2=all) | | `ESC[K` | Erase line (0=to end, 1=to start, 2=all) | | `ESC[m` | SGR: colors 30-37/40-47, bright 90-97/100-107, bold(1), blink(5), reverse(7), reset(0) | | `ESC[s` / `ESC[u` | Save / restore cursor position | | `ESC[S` / `ESC[T` | Scroll up / down | | `ESC[L` / `ESC[M` | Insert / delete lines | | `ESC[?7h/l` | Enable / disable auto-wrap | | `ESC[?25h/l` | Show / hide cursor | Additional functions: ```c void wgtAnsiTermClear(WidgetT *w); // clear + reset cursor int32_t wgtAnsiTermPoll(WidgetT *w); // poll comm for data int32_t wgtAnsiTermRepaint(WidgetT *w, int32_t *y, int32_t *h); // fast dirty-row repaint void wgtAnsiTermSetScrollback(WidgetT *w, int32_t maxLines); ``` ### Spacing and dividers ```c WidgetT *wgtSpacer(WidgetT *parent); // flexible space (weight=100) WidgetT *wgtHSeparator(WidgetT *parent); // horizontal line WidgetT *wgtVSeparator(WidgetT *parent); // vertical line ``` ```c WidgetT *row = wgtHBox(root); wgtButton(row, "Left"); wgtSpacer(row); // pushes next button to the right wgtButton(row, "Right"); ``` ### Tooltips ```c wgtSetTooltip(widget, "Tooltip text appears on hover"); ``` ### Size specifications Size fields (`minW`, `minH`, `maxW`, `maxH`, `prefW`, `prefH`, `spacing`, `padding`) accept tagged values created with: ```c wgtPixels(120) // 120 pixels wgtChars(15) // 15 character widths wgtPercent(50) // 50% of parent ``` A raw `0` means auto (use the widget's natural/computed size). ### Weight The `weight` field controls how extra space is distributed among siblings. When a container is larger than its children's combined minimum size, the surplus is divided proportionally by weight. - `weight = 0` -- fixed size, does not stretch (default for most widgets) - `weight = 100` -- normal stretch (default for spacers and text inputs) - Relative values work: weights of 100, 200, 100 give a 1:2:1 split When all children have weight 0, the container's `align` property determines where children are placed within the extra space. ### Operations ```c void wgtSetText(WidgetT *w, const char *text); const char *wgtGetText(const WidgetT *w); ``` Get/set text for labels, buttons, checkboxes, radios, text inputs, password inputs, masked inputs, combo boxes, and dropdowns. ```c void wgtSetEnabled(WidgetT *w, bool enabled); void wgtSetVisible(WidgetT *w, bool visible); ``` Disabled widgets are drawn grayed out and ignore input. Hidden widgets are excluded from layout. ```c // Disable an entire group of widgets: wgtSetEnabled(btn, false); wgtSetEnabled(slider, false); wgtSetEnabled(textInput, false); ``` ```c void wgtInvalidate(WidgetT *w); ``` Trigger a full relayout and repaint of the widget tree. Call after modifying widget properties, adding/removing widgets, or changing text. ```c void wgtInvalidatePaint(WidgetT *w); ``` Lightweight repaint without relayout. Use when only visual state changed (slider value, cursor blink, checkbox toggle) but widget sizes are stable. ```c WidgetT *wgtFind(WidgetT *root, const char *name); void wgtSetName(WidgetT *w, const char *name); ``` Search the subtree for a widget by name (up to 31 chars). Uses djb2 hash for fast rejection. ```c wgtSetName(statusLabel, "status"); // ... later, from any callback: WidgetT *lbl = wgtFind(root, "status"); wgtSetText(lbl, "Updated!"); wgtInvalidate(lbl); ``` ```c void wgtDestroy(WidgetT *w); ``` Remove a widget and all its children from the tree and free memory. ```c void wgtSetDebugLayout(AppContextT *ctx, bool enabled); ``` When enabled, draws 1px neon-colored borders around all layout containers so their bounds are visible. Each container gets a distinct color derived from its pointer. ### Layout and paint internals These are called automatically by `wgtInvalidate()`, but are available for manual use when embedding the widget system in a custom event loop. ```c int32_t wgtResolveSize(int32_t taggedSize, int32_t parentSize, int32_t charWidth); ``` Convert a tagged size (from `wgtPixels`, `wgtChars`, or `wgtPercent`) to a pixel value given the parent's size and the font's character width. ```c void wgtLayout(WidgetT *root, int32_t availW, int32_t availH, const BitmapFontT *font); ``` Run the two-pass layout engine on the widget tree: measure minimum sizes bottom-up, then distribute available space top-down. Sets `x`, `y`, `w`, `h` on every widget. ```c void wgtPaint(WidgetT *root, DisplayT *d, const BlitOpsT *ops, const BitmapFontT *font, const ColorSchemeT *colors); ``` Paint the entire widget tree into the window's content buffer. --- ## Types reference (`dvxTypes.h`) ### WindowT Core window structure. Key fields: | Field | Type | Description | |-------|------|-------------| | `id` | `int32_t` | Unique window identifier | | `x`, `y`, `w`, `h` | `int32_t` | Outer frame position and size | | `contentX`, `contentY` | `int32_t` | Content area offset within frame | | `contentW`, `contentH` | `int32_t` | Content area dimensions | | `contentBuf` | `uint8_t *` | Pixel buffer (display format) | | `contentPitch` | `int32_t` | Bytes per scanline in content buffer | | `title` | `char[128]` | Title bar text | | `visible` | `bool` | Window is shown | | `focused` | `bool` | Window has input focus | | `minimized` | `bool` | Window is minimized to icon | | `maximized` | `bool` | Window is maximized | | `resizable` | `bool` | Window has resize handles | | `maxW`, `maxH` | `int32_t` | Max dimensions for maximize (-1 = screen) | | `userData` | `void *` | Application data pointer | ### ColorSchemeT All colors are pre-packed via `packColor()`: | Field | Usage | |-------|-------| | `desktop` | Desktop background | | `windowFace` | Window frame fill | | `windowHighlight` | Bevel light edge | | `windowShadow` | Bevel dark edge | | `activeTitleBg/Fg` | Focused title bar | | `inactiveTitleBg/Fg` | Unfocused title bar | | `contentBg/Fg` | Window content area | | `menuBg/Fg` | Menu bar and popups | | `menuHighlightBg/Fg` | Highlighted menu item | | `buttonFace` | Button interior | | `scrollbarBg/Fg/Trough` | Scrollbar elements | ### BitmapFontT Fixed-width bitmap font (8px wide, 14 or 16px tall). Glyphs are packed 1bpp, `charHeight` bytes per glyph, MSB-first. ### BevelStyleT ```c typedef struct { uint32_t highlight; // top/left edge color uint32_t shadow; // bottom/right edge color uint32_t face; // interior fill (0 = no fill) int32_t width; // border thickness in pixels } BevelStyleT; ``` --- ## Window chrome Windows use a Motif/GEOS-style frame: - 4px beveled outer border with perpendicular groove breaks - 20px title bar (dark charcoal background when focused) - Close button on the left edge (requires double-click) - Minimize button on the right edge (always present) - Maximize button to the left of minimize (resizable windows only) - Optional menu bar below the title bar (20px) - Optional scrollbars along the right and bottom edges (16px) Minimized windows appear as 64x64 beveled icons along the bottom of the screen. If a window has an icon image set via `dvxSetWindowIcon()`, that image is shown; otherwise a nearest-neighbor-scaled thumbnail of the window's content buffer is used. Thumbnails are refreshed automatically when the window's content changes, with updates staggered across frames so only one icon redraws per interval. Double-click an icon to restore. ### Keyboard window management | Key | Action | |-----|--------| | Alt+Tab | Cycle windows forward | | Shift+Alt+Tab | Cycle windows backward | | Alt+F4 | Close focused window | | Alt+Space | Open system menu | | F10 | Activate menu bar | --- ## Platform abstraction (`platform/dvxPlatform.h`) All OS-specific code is behind a single interface. To port DVX, implement these functions in a new `dvxPlatformXxx.c`: | Function | Purpose | |----------|---------| | `platformInit()` | One-time setup (signal handling, etc.) | | `platformYield()` | Cooperative multitasking yield | | `platformVideoInit()` | Set up video mode, LFB, backbuffer | | `platformVideoShutdown()` | Restore text mode, free resources | | `platformVideoSetPalette()` | Set 8-bit palette entries | | `platformFlushRect()` | Copy rectangle from backbuffer to LFB | | `platformSpanFill8/16/32()` | Optimized pixel fill | | `platformSpanCopy8/16/32()` | Optimized pixel copy | | `platformMouseInit()` | Initialize mouse driver | | `platformMousePoll()` | Read mouse position and buttons | | `platformKeyboardGetModifiers()` | Read shift/ctrl/alt state | | `platformKeyboardRead()` | Read next key from buffer | | `platformAltScanToChar()` | Map Alt+scancode to ASCII | | `platformValidateFilename()` | Check filename for OS constraints | --- ## Hardware requirements - 486 or later CPU - VESA VBE 2.0+ compatible video card with linear framebuffer support - PS/2 mouse (or compatible mouse driver) - DPMI host (CWSDPMI, Windows DOS box, DOSBox, 86Box) Tested on 86Box with PCI video cards. DOSBox is a trusted reference platform.