> For the complete documentation index, see [llms.txt](https://www.lisppad.app/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://www.lisppad.app/libraries/lisppad/system-ios.md). # (lisppad system ios) Library `(lisppad system ios)` implements a simple API for LispPad Go-specific system procedures. Procedures matching the same functionality on macOS are also available via library `(lisppad system)`. ## Files **(project-directory)** Returns the path to the documents directory of LispPad Go, where local files are stored. **(icloud-directory)** Returns the path to the iclouds directory of LispPad Go, where files are stored that are synchronized via iCloud. This procedure returns `#f` if iCloud synchronization is not enabled. **(icloud-list)** Returns a list of file paths of all LispPad-related files that are synchronized via iCloud. The paths are relative to the iCloud directory which can be obtained via procedure `icloud-directory`. **(preview-file *****path*****)** Shows a preview of the content of the file at the given file path *path*. Supported are many different types of files, including text files, images, PDF files, spreadsheets, etc. **(share-file *****path*****)** Shows a file share panel for the file at file path *path*, allowing the user to share the file with another application. **(open-in-files-app *****path*****)** Opens the Files app at the given file path *path*. ## Images **(save-bitmap-in-library *****img*****)** Saves the given bitmap-based image *img* in the photo library of the user. The first time this procedure gets invoked, it asks the user for permission to access the photo library. **(load-bitmaps-from-library)** \ **(load-bitmaps-from-library *****max*****)**\ **(load-bitmaps-from-library *****max filter*****)** Opens an image selector showing the images of the user's photo library. The user can select up to *max* images from the photo library. These are returned by procedure `load-bitmaps-from-library` as a list of images. *filter* is an image filter for narrowing down the types of images that are shown. *filter* has either the form of: * a symbol, indicating a type of images (e.g. `bursts`, `panoramas`, `videos`), * `(not` *filter* `)`, indicating the inverse of *filter*, * `(and` *filter* ... `)`, indicating the conjunction of the given filters, or * `(or` *filter* ... `)`, indicating the disjunction of the given filters. The following image type tags, expressed as a symbol, are supported: `bursts`, `cinematic-videos`, `depth-effect-photos`, `images`, `live-photos`, `panoramas`, `screen-recordings`, `screenshots`, `slomo-videos`, `timelapse-videos`, and `videos`. The default is `images`. **(load-bytevectors-from-library)** \ **(load-bytevectors-from-library *****max*****)**\ **(load-bytevectors-from-library *****max filter*****)** Opens an image selector showing the images of the user's photo library. The user can select up to *max* images from the photo library. These are returned by procedure `load-bytevectors-from-library` as a list of bytevectors. *filter* is an image filter for narrowing down the types of images that are shown, as documented for procedure `load-bitmaps-from-library`. `load-bytevectors-from-library` is useful if one is dealing with videos or other types of data that are not supported natively. ## Interaction **(show-message-panel *****title*****)** \ **(show-message-panel *****title message*****)**\ **(show-message-panel *****title message button*****)** Shows a message panel (an alert) with the given *title* and *message*, and a single button labeled *button* for dismissing it. If *title* is `#f`, the title `"Alert"` is used. If *message* is not provided or `#f`, no message text is shown. If *button* is not provided or `#f`, the button is labeled `"OK"`. `show-message-panel` returns an unspecified value once the panel was dismissed by the user, or `#f` if the panel could not be displayed. **(show-confirmation-panel *****title message*****)** \ **(show-confirmation-panel *****title message yes*****)**\ **(show-confirmation-panel *****title message yes no*****)** Shows a confirmation panel with the given *title* and *message*, providing two buttons for confirming (labeled *yes*) or rejecting (labeled *no*) the request. If *title* is `#f`, the title `"Confirm"` is used. If *yes* is not provided or `#f`, the confirmation button is labeled `"Yes"`. If *no* is not provided or `#f`, the rejection button is labeled `"No"`. Procedure `show-confirmation-panel` returns `#t` if the user confirms the request, and `#f` if the user rejects it or the panel could not be displayed. **(show-choice-panel *****title message options*****)** \ **(show-choice-panel *****title message options selected*****)**\ **(show-choice-panel *****title message options selected confirm*****)** Shows a choice panel with the given *title* and *message*, letting the user pick one alternative from list *options*. Each element of *options* is either a string, or a pair whose first component is a string used as the label of the alternative. *selected* is a string identifying the label of the alternative that is selected initially; if *selected* is not provided or `#f`, no alternative is pre-selected. *confirm* is the label of the button used to confirm the selection; the default is `"Select"`. Procedure `show-choice-panel` returns the zero-based index of the alternative chosen by the user within *options*, or `#f` if the choice was cancelled or the panel could not be displayed. **(show-input-panel *****title message*****)** \ **(show-input-panel *****title message initial*****)**\ **(show-input-panel *****title message initial placeholder*****)**\ **(show-input-panel *****title message initial placeholder confirm*****)** Shows an input panel with the given *title* and *message*, letting the user enter a line of text. *initial* is the text shown initially in the input field; the default is the empty string. *placeholder* is a placeholder text shown when the input field is empty; the default is the empty string. *confirm* is the label of the button used to confirm the input; the default is `"OK"`. Procedure `show-input-panel` returns the string entered by the user, or `#f` if the input was cancelled or the panel could not be displayed. **(show-date-panel *****title message type*****)** \ **(show-date-panel *****title message type initial*****)**\ **(show-date-panel *****title message type initial range*****)**\ **(show-date-panel *****title message type initial range tz*****)**\ **(show-date-panel *****title message type initial range tz confirm*****)**\ **(show-date-panel *****title message type initial range tz confirm cancel*****)** Shows a date panel with the given *title* and *message*, letting the user pick a date, a range of dates, or several dates, depending on *type*. *type* is one of the symbols `single`, `range`, or `multiple`: * If *type* is `single`, *initial* is either `#f` (no date pre-selected) or a date-time object representing the initially selected date. `show-date-panel` returns a date-time object for the date picked by the user, or `#f` if the panel was cancelled. * If *type* is `range`, *initial* is either `#f` (no range pre-selected) or a pair of two date-time objects representing the lower and upper bound of the initially selected range. `show-date-panel` returns a pair of two date-time objects for the range picked by the user, or `#f` if the panel was cancelled. * If *type* is `multiple`, *initial* is either `#f` (no dates pre-selected) or a list of date-time objects representing the initially selected dates. `show-date-panel` returns a list of date-time objects for the dates picked by the user, or `#f` if the panel was cancelled. *range* restricts the dates that can be selected to a given interval. It is either `#f` (no restriction) or a pair of two date-time objects representing the lower and upper bound of the selectable interval. *tz* specifies the time zone used for interpreting and returning date-time values. It is either `#f` (the current, operating-system defined time zone is used), a number representing an offset from GMT in seconds, a symbol referring to a time zone abbreviation (e.g. `PST`), or a string referring to a time zone identifier (e.g. `"America/Los_Angeles"`) or a time zone abbreviation. If *title* or *message* is `#f`, no title, respectively no message, is shown. *confirm* and *cancel* are the labels of the buttons used to confirm (default `"Select"`) and cancel (default `"Cancel"`) the panel. Procedure `show-date-panel` also returns `#f` if the panel could not be displayed. **(show-preview-panel *****obj*****)** \ **(show-preview-panel *****obj type*****)** Shows a preview of *obj* when possible. Supported are the following types of data: strings (textual data), bytevectors (binary data), styled text, images, and drawings. For strings and bytevectors it is important that parameter *type* is used to narrow down the type of content. *type* is a string representing a "file extension". Supported are at least: `"png"`, `"jpg"`, `"jpeg"`, `"gif"`, `"bmp"`, `"tif"`, `"tiff"`, `"text"`, `"txt"`, `"markdown"`, `"md"`, `"html"`, `"rtf"`, and `"rtfd"`. Other *type* extensions might work. **(show-share-panel *****obj*****)** \ **(show-share-panel *****obj type*****)** Shows a panel for sharing *obj* with other applications when possible. Supported are the following types of data: strings (textual data), bytevectors (binary data), styled text, images, and drawings. For strings and bytevectors it is important that parameter *type* is used to narrow down the type of content. *type* is a string representing a "file extension". Supported are at least: `"png"`, `"jpg"`, `"jpeg"`, `"gif"`, `"bmp"`, `"tif"`, `"tiff"`, `"text"`, `"txt"`, `"markdown"`, `"md"`, `"html"`, `"rtf"`, and `"rtfd"`. Other *type* extensions might work. **(show-load-panel *****prompt folders filetypes*****)** Displays a file load panel with the given *prompt* message. *folders* is a boolean argument; it should be set to `#t` if the user is required to select a folder. *filetypes* is a list of suffixes of selectable file types. **(show-save-panel *****prompt*****)** \ **(show-save-panel *****prompt path*****)**\ **(show-save-panel *****prompt path locked*****)** Displays a file save panel with the given *prompt* message. *path* might refer to a pre-selected file. Boolean argument *locked* determines if the folder (provided via *path*) may be changed or not. **(show-interpreter-tab *****tab*****)** \ **(show-interpreter-tab *****tab canvas*****)** LispPad Go has three interpreter views: the console view, the log view, and the canvas view. Procedure `show-interpreter-tab` enables programmatic navigation between these three views. *tab* is one of the following three symbols: `console`, `log`, and `canvas`. If *tab* is `canvas`, then a second argument *canvas* can be provided referring to a canvas to select. **(show-help *****name*****)** Shows documentation for identifier *name* (symbol or string), if available. ## Canvases A canvas shows a drawing in the canvas view of the interpreter. The following parameters can be configured for every canvas: the drawing, the size of the canvas, a scale factor (default is 1.0), and an optional background color. Canvases are identified by a fixnum identifier. **(make-canvas *****drawing size*****)** \ **(make-canvas *****drawing size name*****)**\ **(make-canvas *****drawing size name color*****)** Creates a new canvas of *size* showing *drawing*. String *name* is used to identify the canvas in the user interface. If *name* is not provided, a unqiue name is generated. *color* is the background color of the new canvas. `make-canvas` returns a canvas identifier (fixnum), which is used to refer to canvases in the API. **(use-canvas *****drawing size*****)** \ **(use-canvas *****drawing size name*****)**\ **(use-canvas *****drawing size name color*****)** Creates or reuses a canvas of *size* showing *drawing*. If there is already an existing canvas of the same *name*, it is reused and reconfigured. Otherwise, a new canvas is created. *color* is the background color of the canvas. `use-canvas` returns a canvas identifier (fixnum), which is used to refer to canvases in the API. **(close-canvas *****canvas*****)** Closes *canvas*. *canvas* is either a canvas identifier (fixnum) or it is a name of a canvas (string). `close-canvas` returns `#t` if a canvas was closed, otherwise `#f` is returned. **(canvas-name *****canvas*****)** Returns the name of *canvas* as a string. *canvas* is either a canvas identifier (fixnum) or it is a name of a canvas (string). It is an error if no matching canvas was found. **(set-canvas-name! *****canvas name*****)** Sets the name of *canvas* to string *name*. *canvas* is either a canvas identifier (fixnum) or it is a name of a canvas (string). It is an error if no matching canvas was found. **(canvas-size *****canvas*****)** Returns the size of *canvas*. *canvas* is either a canvas identifier (fixnum) or it is a name of a canvas (string). It is an error if no matching canvas was found. **(set-canvas-size! *****canvas size*****)** Sets the size of *canvas* to *size*. *canvas* is either a canvas identifier (fixnum) or it is a name of a canvas (string). It is an error if no matching canvas was found. **(canvas-scale *****canvas*****)** Returns the scale factor used by *canvas*. The default is 1.0. *canvas* is either a canvas identifier (fixnum) or it is a name of a canvas (string). It is an error if no matching canvas was found. **(set-canvas-scale! *****canvas scale*****)** Sets the scale factor used by *canvas* to number *scale*. *canvas* is either a canvas identifier (fixnum) or it is a name of a canvas (string). It is an error if no matching canvas was found. **(canvas-background *****canvas*****)** Returns the background color of *canvas* if one was defined, or `#f` if no background color was set. *canvas* is either a canvas identifier (fixnum) or it is a name of a canvas (string). It is an error if no matching canvas was found. **(set-canvas-background! *****canvas color*****)** Sets the background color of *canvas* to *color* (color or `#f`). *canvas* is either a canvas identifier (fixnum) or it is a name of a canvas (string). It is an error if no matching canvas was found. **(canvas-drawing *****canvas*****)** Returns the drawing shown by *canvas*. *canvas* is either a canvas identifier (fixnum) or it is a name of a canvas (string). It is an error if no matching canvas was found. **(set-canvas-drawing! *****canvas drawing*****)** Sets the background color of *canvas* to *drawing*. *canvas* is either a canvas identifier (fixnum) or it is a name of a canvas (string). It is an error if no matching canvas was found. ## Sessions **(session-id)** Returns a unique fixnum (within LispPad Go) identifying the interpreter session. The number changes when the interpreter is reset or the application is restarted. **(session-name)** Returns the name of the LispPad session which executes this function. This name is customizable on macOS. On iOS, the name is generated using the session id. **(session-log *****time sev str*****)** \ **(session-log *****time sev str tag*****)** Logs the message *str* with severity *sev* at the given timestamp *time* (a double value) in the session log. *sev* is one of the following symbols: `debug`, `info`, `warn`, `error`, or `fatal`. ## Environment **(screen-size)** Returns the screen size of the screen of the device running LispPad Go. **(dark-mode?)** Return `#t` if the device on which LispPad Go is running is using *dark mode*; returns `#f` otherwise.