<![CDATA[DandeGUI now does graphics and this is what it looks like. Some text and graphics output windows created with DandeGUI on Medley Interlisp. In addition to the square root table text output demo, I created the other graphics windows with the newly implemented functionality. For example, this code draws the random circles of the top window: (DEFUN RANDOM-CIRCLES (&KEY (N 200) (MAX-R 50) (WIDTH 640) (HEIGHT 480)) (LET ((RANGE-X (- WIDTH ( 2 MAX-R))) (RANGE-Y (- HEIGHT ( 2 MAX-R))) (SHADES (LIST IL:BLACKSHADE IL:GRAYSHADE (RANDOM 65536)))) (DANDEGUI:WITH-GRAPHICS-WINDOW (STREAM :TITLE "Random Circles") (DOTIMES (I N) (DECLARE (IGNORE I)) (IL:FILLCIRCLE (+ MAX-R (RANDOM RANGE-X)) (+ MAX-R (RANDOM RANGE-Y)) (RANDOM MAX-R) (ELT SHADES (RANDOM 3)) STREAM))))) GUI:WITH-GRAPHICS-WINDOW, GUI:OPEN-GRAPHICS-STREAM, and GUI:WITH-GRAPHICS-STREAM are the main additions. These functions and macros are the equivalent for graphics of what GUI:WITH-OUTPUT-TO-WINDOW, GUI:OPEN-WINDOW-STREAM, and GUI:WITH-WINDOW-STREAM, respectively, do for text. The difference is the text facilities send output to TEXTSTREAM streams whereas the graphics facilities to IMAGESTREAM, a type of device-independent graphics streams. Under the hood DandeGUI text windows are customized TEdit windows with an associated TEXTSTREAM. TEdit is the rich text editor of Medley Interlisp. Similarly, the graphics windows of DandeGUI run the Sketch line drawing editor under the hood. Sketch windows have an IMAGESTREAM which Interlisp graphics primitives like IL:DRAWLINE and IL:DRAWPOINT accept as an output destination. DandeGUI creates and manages Sketch windows with the type of stream the graphics primitives require. In other words, IMAGESTREAM is to Sketch what TEXTSTREAM is to TEdit. The benefits of programmatically using Sketch for graphics are the same as TEdit windows for text: automatic window repainting, scrolling, and resizing. The downside is overhead. Scrolling more than a few thousand graphics elements is slow and adding even more may crash the system. However, this is an acceptable tradeoff. The new graphics functions and macros work similarly to the text ones, with a few differences. First, DandeGUI now depends on the SKETCH and SKETCH-STREAM library modules which it automatically loads. Since Sketch has no notion of a read-only drawing area GUI:OPEN-GRAPHICS-STREAM achieves the same effect by other means: (DEFUN OPEN-GRAPHICS-STREAM (&KEY (TITLE "Untitled")) "Open a new window and return the associated IMAGESTREAM to send graphics output to. Sets the window title to TITLE if supplied." (LET ((STREAM (IL:OPENIMAGESTREAM '|Untitled| 'IL:SKETCH '(IL:FONTS ,DEFAULT-FONT*))) (WINDOW (IL:\\SKSTRM.WINDOW.FROM.STREAM STREAM))) (IL:WINDOWPROP WINDOW 'IL:TITLE TITLE) ;; Disable left and middle-click title bar menu (IL:WINDOWPROP WINDOW 'IL:BUTTONEVENTFN NIL) ;; Disable sketch editing via right-click actions (IL:WINDOWPROP WINDOW 'IL:RIGHTBUTTONFN NIL) ;; Disable querying the user whether to save changes (IL:WINDOWPROP WINDOW 'IL:DONTQUERYCHANGES T) STREAM)) Only the mouse gestures and commands of the middle-click title bar menu and the right-click menu change the drawing area interactively. To disable these actions GUI:OPEN-GRAPHICS-STREAM removes their menu handlers by setting to NIL the window properties IL:BUTTONEVENTFN and IL:RIGHTBUTTONFN. This way only programmatic output can change the drawing area. The function also sets IL:DONTQUERYCHANGES to T to prevent querying whether to save the changes at window close. By design output to DandeGUI windows is not permanent, so saving isn't necessary. GUI:WITH-GRAPHICS-STREAM and GUI:WITH-GRAPHICS-WINDOW are straightforward: (DEFMACRO WITH-GRAPHICS-STREAM ((VAR STREAM) &BODY BODY) "Perform the operations in BODY with VAR bound to the graphics window STREAM. Evaluates the forms in BODY in a context in which VAR is bound to STREAM which must already exist, then returns the value of the last form of BODY." `(LET ((,VAR ,STREAM)) ,@BODY)) (DEFMACRO WITH-GRAPHICS-WINDOW ((VAR &KEY TITLE) &BODY BODY) "Perform the operations in BODY with VAR bound to a new graphics window stream. Creates a new window titled TITLE if supplied, binds VAR to the IMAGESTREAM associated with the window, and executes BODY in this context. Returns the value of the last form of BODY." `(WITH-GRAPHICS-STREAM (,VAR (OPEN-GRAPHICS-STREAM :TITLE (OR ,TITLE "Untitled"))) ,@BODY)) Unlike GUI:WITH-TEXT-STREAM and GUI:WITH-TEXT-WINDOW, which need to call GUI::WITH-WRITE-ENABLED to establish a read-only environment after every output operation, GUI:OPEN-GRAPHICS-STREAM can do this only once at window creation. GUI:CLEAR-WINDOW, GUI:WINDOW-TITLE, and GUI:PRINT-MESSAGE now work with graphics streams in addition to text streams. For IMAGESTREAM arguments GUI:PRINT-MESSAGE prints to the system prompt window as Sketch stream windows have no prompt area. The random circles and fractal triangles graphics demos round up the latest additions. #DandeGUI #CommonLisp #Interlisp #Lisp a href="https://remark.as/p/journal.paoloamoroso.com/adding-graphics-support-to-dandegui"Discuss.../a Email | Reply @amoroso@oldbytes.space !--emailsub--]]>

<![CDATA[Printing rich text to windows is one of the planned features of DandeGUI, the GUI library for Medley Interlisp I'm developing in Common Lisp. I finally got around to this and implemented the GUI:WITH-TEXT-STYLE macro which controls the attributes of text printed to a window, such as the font family and face. GUI:WITH-TEXT-STYLE establishes a context in which text printed to the stream associated with a TEdit window is rendered in the style specified by the arguments. The call to GUI:WITH-TEXT-STYLE here extends the square root table example by printing the heading in a 12-point bold sans serif font: (gui:with-output-to-window (stream :title "Table of square roots") (gui:with-text-style (stream :family :sans :size 12 :face :bold) (format stream "~&Number~40TSquare Root~2%")) (loop for n from 1 to 30 do (format stream "~&~4D~40T~8,4F~%" n (sqrt n)))) The code produces this window in which the styled column headings stand out: Medley Interlisp window of a square root table generated by the DandeGUI GUI library. The :FAMILY, :SIZE, and :FACE arguments determine the corresponding text attributes. :FAMILY may be a generic family such as :SERIF for an unspecified serif font; :SANS for a sans serif font; :FIX for a fixed width font; or a keyword denoting a specific family like :TIMESROMAN. At the heart of GUI:WITH-TEXT-STYLE is a pair of calls to the Interlisp function PRINTOUT that wrap the macro body, the first for setting the font of the stream to the specified style and the other for restoring the default: (DEFMACRO WITH-TEXT-STYLE ((STREAM &KEY FAMILY SIZE FACE) &BODY BODY) (ONCE-ONLY (STREAM) `(UNWIND-PROTECT (PROGN (IL:PRINTOUT ,STREAM IL:.FONT (TEXT-STYLE-TO-FD ,FAMILY ,SIZE ,FACE)) ,@BODY) (IL:PRINTOUT ,STREAM IL:.FONT DEFAULT-FONT)))) PRINTOUT is an Interlisp function for formatted output similar to Common Lisp's FORMAT but with additional font control via the .FONT directive. The symbols of PRINTOUT, i.e. its directives and arguments, are in the Interlisp package. In turn GUI:WITH-TEXT-STYLE calls GUI::TEXT-STYLE-TO-FD, an internal DandeGUI function which passes to .FONT a font descriptor matching the required text attributes. GUI::TEXT-STYLE-TO-FD calls IL:FONTCOPY to build a descriptor that merges the specified attributes with any unspecified ones copied from the default font. The font descriptor is an Interlisp data structure that represents a font on the Medley environment. #DandeGUI #CommonLisp #Interlisp #Lisp a href="https://remark.as/p/journal.paoloamoroso.com/changing-text-style-for-dandegui-window-output"Discuss.../a Email | Reply @amoroso@oldbytes.space !--emailsub--]]>

<![CDATA[I'm working on DandeGUI, a Common Lisp GUI library for simple text and graphics output on Medley Interlisp. The name, pronounced "dandy guy", is a nod to the Dandelion workstation, one of the Xerox D-machines Interlisp-D ran on in the 1980s. DandeGUI allows the creation and management of windows for stream-based text and graphics output. It captures typical GUI patterns of the Medley environment such as printing text to a window instead of the standard output. The main window of this screenshot was created by the code shown above it. A text output window created with DandeGUI on Medley Interlisp and the Lisp code that generated it. The library is written in Common Lisp and exposes its functionality as an API callable from Common Lisp and Interlisp code. Motivations In most of my prior Lisp projects I wrote programs that print text to windows. In general these windows are actually not bare Medley windows but running instances of the TEdit rich-text editor. Driving a full editor instead of directly creating windows may be overkill, but I get for free content scrolling as well as window resizing and repainting which TEdit handles automatically. Moreover, TEdit windows have an associated TEXTSTREAM, an Interlisp data structure for text stream I/O. A TEXTSTREAM can be passed to any Common Lisp or Interlisp output function that takes a stream as an argument such as PRINC, FORMAT, and PRIN1. For example, if S is the TEXTSTREAM associated with a TEdit window, (FORMAT S "~&Hello, Medley!~%") inserts the text "Hello, Medley!" in the window at the position of the cursor. Simple and versatile. As I wrote more GUI code, recurring patterns and boilerplate emerged. These programs usually create a new TEdit window; set up the title and other options; fetch the associated text stream; and return it for further use. The rest of the program prints application specific text to the stream and hence to the window. These patterns were ripe for abstracting and packaging in a library that other programs can call. This work is also good experience with API design. Usage An example best illustrates what DandeGUI can do and how to use it. Suppose you want to display in a window some text such as a table of square roots. This code creates the table in the screenshot above: (gui:with-output-to-window (stream :title "Table of square roots") (format stream "~&Number~40TSquare Root~2%") (loop for n from 1 to 30 do (format stream "~&~4D~40T~8,4F~%" n (sqrt n)))) DandeGUI exports all the public symbols from the DANDEGUI package with nickname GUI. The macro GUI:WITH-OUTPUT-TO-WINDOW creates a new TEdit window with title specified by :TITLE, and establishes a context in which the variable STREAM is bound to the stream associated with the window. The rest of the code prints the table by repeatedly calling the Common Lisp function FORMAT with the stream. GUI:WITH-OUTPUT-TO-WINDOW is best suited for one-off output as the stream is no longer accessible outside of its scope. To retain the stream and send output in a series of steps, or from different parts of the program, you need a combination of GUI:OPEN-WINDOW-STREAM and GUI:WITH-WINDOW-STREAM. The former opens and returns a new window stream which may later be used by FORMAT and other stream output functions. These functions must be wrapped in calls to the macro GUI:WITH-WINDOW-STREAM to establish a context in which a variable is bound to the appropriate stream. The DandeGUI documentation on the project repository provides more details, sample code, and the API reference. Design DandeGUI is a thin wrapper around the Interlisp system facilities that provide the underlying functionality. The main reason for a thin wrapper is to have a simple API that covers the most common user interface patterns. Despite the simplicity, the library takes care of a lot of the complexity of managing Medley GUIs such as content scrolling and window repainting and resizing. A thin wrapper doesn't hide much the data structures ubiquitous in Medley GUIs such as menus and font descriptors. This is a plus as the programmer leverages prior knowledge of these facilities. So far I have no clear idea how DandeGUI may evolve. One more reason not to deepen the wrapper too much without a clear direction. The user needs not know whether DandeGUI packs TEdit or ordinary windows under the hood. Therefore, another design goal is to hide this implementation detail. DandeGUI, for example, disables the main command menu of TEdit and sets the editor buffer to read-only so that typing in the window doesn't change the text accidentally. Using Medley Common Lisp DandeGUI relies on basic Common Lisp features. Although the Medley Common Lisp implementation is not ANSI compliant it provides all I need, with one exception. The function DANDEGUI:WINDOW-TITLE returns the title of a window and allows to set it with a SETF function. However, the SEdit structure editor and the File Manager of Medley don't support or track function names that are lists such as (SETF WINDOW-TITLE). A good workaround is to define SETF functions with DEFSETF which Medley does support along with the CLtL macro DEFINE-SETF-METHOD. Next steps At present DandeGUI doesn't do much more than what described here. To enhance this foundation I'll likely allow to clear existing text and give control over where to insert text in windows, such as at the beginning or end. DandeGUI will also have rich text facilities like printing in bold or changing fonts. The windows of some of my programs have an attached menu of commands and a status area for displaying errors and other messages. I will eventually implement such menu-ed windows. To support programs that do graphics output I plan to leverage the functionality of Sketch for graphics in a way similar to how I build upon TEdit for text. Sketch is the line drawing editor of Medley. The Interlisp graphics primitives require as an argument a DISPLAYSTREAM, a data stracture that represents an output sink for graphics. It is possible to use the Sketch drawing area as an output destination by associating a DISPLAYSTREAM with the editor's window. Like TEdit, Sketch takes care of repainting content as well as window scrolling and resizing. In other words, DISPLAYSTREAM is to Sketch what TEXTSTREAM is to TEdit. DandeGUI will create and manage Sketch windows with associated streams suitable for use as the DISPLAYSTREAM the graphics primitives require. #DandeGUI #CommonLisp #Interlisp #Lisp a href="https://remark.as/p/journal.paoloamoroso.com/dandegui-a-gui-library-for-medley-interlisp"Discuss.../a Email | Reply @amoroso@fosstodon.org !--emailsub--]]>

<![CDATA[I spoke too soon when I said I was enjoying the stability of Linux. I have been using Linux Mint Cinnamon on a System76 Merkaat PC with no major issues since July of 2024. But a few days ago a routine system update of Mint 22 dumped me to the text console. A fresh install of Mint 22.1, the latest release, brought the system back online. I had backups and the mishap luckily turned out as just an annoyance that consumed several hours of unplanned maintenance. It all started when the Mint Update Manager listed several packages for update, including the System76 driver and tools. Oddly, the Update Manager also marked for removal several packages including core ones such as Xorg, Celluloid, and more. The smooth running of Mint made my paranoid side fall asleep and I applied the recommend changes. At the next reboot the graphics session didn't start and landed me at the text console with no clue what happened. I don't use Timeshift for system snapshots as I prefer a fresh install and restore of data backups if the system breaks. Therefore, to fix such an issue apparently related to Mint 22 the obvious route was to install Mint 22.1. Besides, this was the right occasion to try the new release. On my Raspberry Pi 400 I ran dd to flash a bootable USB stick with Mint 22.1. I had no alternatives as GNOME Disks didn't work. The Merkaat failed to boot off the stick, possibly because I messed with the arguments of dd. I still had around a USB stick with Mint 22 and I used it to freshly install it on the Merkaat. Then I immediately ran the upgrade to Mint 22.1 which completed successfully unlike a prior upgrade attempt. Next, I tried to install the System76 driver with sudo apt install system76-driver but got a package not found error. At that point I had already added the System76 package repository to the APT sources and refreshing the Mint Update Manager yielded this error: Could not refresh the list of updates Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages Aside from the errors the system was up and running on the Merkaat, so with Nemo I reflashed the Mint 22.1 stick. This time the PC did boot off the stick and let me successfully install Mint 22.1. Restoring the data completed the system recovery. I left out the System76 driver as it's the primary suspect, possibly due to package conflicts. Mint detects and supports all hardware of the Merkaat anyway and it's only prudent to skip the package for the time being. Besides improvements under the hood, Mint 22.1 features a redesigned default Cinnamon theme. No major changes, I feel at home. The main takeaway of this adventure is that it's better to have a bootable USB stick ready with the latest Mint release, even if I don't plan to upgrade immediately. Another takeaway is the Pi 400 makes for a viable backup computer that can support my major tasks, should it take longer to recover the Merkaat. However, using the device for making bootable media is problematic as little flashing software is available and some is unreliable. Finally, over decades of Linux experience I honed my emergency installation skills so much I can now confidently address most broken system situations. #linux #pi400 a href="https://remark.as/p/journal.paoloamoroso.com/an-unplanned-upgrade-to-linux-mint-22-1-cinnamon"Discuss.../a Email | Reply @amoroso@fosstodon.org !--emailsub--]]>