Enabling latex async generation by default, default LaTeX setting now depends on state of installation.

common/src/module/canvas.mjs

@@ -30,6 +30,8 @@ class CanvasAPI extends Module {
     #canvas = null
     /** @type {CanvasRenderingContext2D} */
     #ctx = null
+    /** Lock to prevent asynchronous stuff from printing stuff that is outdated. */
+    #redrawCount = 0
     /** @type {{show(string, string, string)}} */
     #drawingErrorDialog = null
 
@@ -207,6 +209,7 @@ class CanvasAPI extends Module {
      */
     redraw() {
         if(!this.initialized) throw new Error("Attempting redraw before initialize!")
+        this.#redrawCount = (this.#redrawCount + 1) % 10000
         this.#ctx = this.#canvas.getContext("2d")
         this._computeAxes()
         this._reset()
@@ -519,15 +522,18 @@ class CanvasAPI extends Module {
      * @param {function(LatexRenderResult|{width: number, height: number, source: string})} callback
      */
     renderLatexImage(ltxText, color, callback) {
+        const currentRedrawCount = this.#redrawCount
         const onRendered = (imgData) => {
             if(!this.#canvas.isImageLoaded(imgData.source) && !this.#canvas.isImageLoading(imgData.source)) {
                 // Wait until the image is loaded to callback.
                 this.#canvas.loadImageAsync(imgData.source).then(() => {
-                    callback(imgData)
+                    if(this.#redrawCount === currentRedrawCount)
+                        callback(imgData)
                 })
             } else {
                 // Callback directly
-                callback(imgData)
+                if(this.#redrawCount === currentRedrawCount)
+                    callback(imgData)
             }
         }
         const prerendered = Latex.findPrerendered(ltxText, this.textsize, color)

common/src/module/interface.mjs

@@ -84,13 +84,21 @@ export class DialogInterface extends Interface {
 }
 
 export class LatexInterface extends Interface {
+    supportsAsyncRender = BOOLEAN
     /**
      * @param {string} markup - LaTeX markup to render
      * @param {number} fontSize - Font size (in pt) to render
      * @param {string} color - Color of the text to render
      * @returns {string} - Comma separated data of the image (source, width, height)
      */
-    render = FUNCTION
+    renderSync = FUNCTION
+    /**
+     * @param {string} markup - LaTeX markup to render
+     * @param {number} fontSize - Font size (in pt) to render
+     * @param {string} color - Color of the text to render
+     * @returns {Promise<string>} - Comma separated data of the image (source, width, height)
+     */
+    renderAsync = FUNCTION
     /**
      * @param {string} markup - LaTeX markup to render
      * @param {number} fontSize - Font size (in pt) to render

common/src/module/latex.mjs

@@ -112,7 +112,12 @@ class LatexAPI extends Module {
      */
     async requestAsyncRender(markup, fontSize, color) {
         if(!this.initialized) throw new Error("Attempting requestAsyncRender before initialize!")
-        let args = this.#latex.render(markup, fontSize, color).split(",")
+        let render
+        if(this.#latex.supportsAsyncRender)
+            render = await this.#latex.renderAsync(markup, fontSize, color)
+        else
+            render = this.#latex.renderSync(markup, fontSize, color)
+        const args = render.split(",")
         return new LatexRenderResult(...args)
     }
 

common/src/preferences/general.mjs

@@ -46,8 +46,15 @@ class EnableLatex extends BoolSetting {
     }
 }
 
+const ENABLE_LATEX_ASYNC = new BoolSetting(
+    qsTranslate("general", "Enable asynchronous LaTeX renderer"),
+    "enable_latex_async",
+    "new"
+)
+
 export default [
     CHECK_FOR_UPDATES,
     RESET_REDO_STACK,
-    new EnableLatex()
+    new EnableLatex(),
+    ENABLE_LATEX_ASYNC
 ]

runtime-pyside6/LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/Popup/Changelog.qml

@@ -45,17 +45,17 @@ Popup {
     property bool changelogNeedsFetching: true
     
     onAboutToShow: if(changelogNeedsFetching) {
-        Helper.fetchChangelog()
-    }
-    
-    Connections {
-        target: Helper
-        function onChangelogFetched(chl) {
-            changelogNeedsFetching = false;
-            changelog.text = chl
+        Helper.fetchChangelog().then((fetchedText) => {
+            changelogNeedsFetching = false
+            changelog.text = fetchedText
             changelogView.contentItem.implicitHeight = changelog.height
-            // console.log(changelog.height, changelogView.contentItem.implicitHeight)
-        }
+        }, (error) => {
+            const e = qsTranslate("changelog", "Could not fetch update: {}.").replace('{}', error)
+            console.error(e)
+            changelogNeedsFetching = false
+            changelog.text = e
+            changelogView.contentItem.implicitHeight = changelog.height
+        })
     }
 
     ScrollView {

runtime-pyside6/LogarithmPlotter/util/config.py

@@ -19,13 +19,16 @@
 from os import path, environ, makedirs
 from platform import system
 from json import load, dumps
+from shutil import which
+
 from PySide6.QtCore import QLocale, QTranslator
 
 DEFAULT_SETTINGS = {
     "check_for_updates": True,
     "reset_redo_stack": True,
     "last_install_greet": "0",
-    "enable_latex": False,
+    "enable_latex": which("latex") is not None and which("dvipng") is not None,
+    "enable_latex_async": True,
     "expression_editor": {
         "autoclose": True,
         "colorize": True,

runtime-pyside6/LogarithmPlotter/util/helper.py

@@ -29,13 +29,16 @@ from urllib.error import HTTPError, URLError
 
 from LogarithmPlotter import __VERSION__
 from LogarithmPlotter.util import config
+from LogarithmPlotter.util.promise import PyPromise
 
 SHOW_GUI_MESSAGES = "--test-build" not in argv
 CHANGELOG_VERSION = __VERSION__
+CHANGELOG_CACHE_PATH = path.join(path.dirname(path.realpath(__file__)), "CHANGELOG.md")
 
 
 class InvalidFileException(Exception): pass
 
+
 def show_message(msg: str) -> None:
     """
     Shows a GUI message if GUI messages are enabled
@@ -46,31 +49,30 @@ def show_message(msg: str) -> None:
         raise InvalidFileException(msg)
 
 
+def fetch_changelog():
+    msg_text = "Unknown changelog error."
+    try:
+        # Fetching version
+        r = urlopen("https://api.ad5001.eu/changelog/logarithmplotter/?version=" + CHANGELOG_VERSION)
+        lines = r.readlines()
+        r.close()
+        msg_text = "".join(map(lambda x: x.decode('utf-8'), lines)).strip()
+    except HTTPError as e:
+        msg_text = QCoreApplication.translate("changelog", "Could not fetch changelog: Server error {}.").format(
+            str(e.code))
+    except URLError as e:
+        msg_text = QCoreApplication.translate("changelog", "Could not fetch update: {}.").format(str(e.reason))
+    return msg_text
 
-class ChangelogFetcher(QRunnable):
-    def __init__(self, helper):
-        QRunnable.__init__(self)
-        self.helper = helper
 
-    def run(self):
-        msg_text = "Unknown changelog error."
-        try:
-            # Fetching version
-            r = urlopen("https://api.ad5001.eu/changelog/logarithmplotter/?version=" + CHANGELOG_VERSION)
-            lines = r.readlines()
-            r.close()
-            msg_text = "".join(map(lambda x: x.decode('utf-8'), lines)).strip()
-        except HTTPError as e:
-            msg_text = QCoreApplication.translate("changelog", "Could not fetch changelog: Server error {}.").format(
-                str(e.code))
-        except URLError as e:
-            msg_text = QCoreApplication.translate("changelog", "Could not fetch update: {}.").format(str(e.reason))
-        self.helper.changelogFetched.emit(msg_text)
+def read_changelog():
+    f = open(CHANGELOG_CACHE_PATH, 'r', -1)
+    data = f.read().strip()
+    f.close()
+    return data
 
 
 class Helper(QObject):
-    changelogFetched = Signal(str)
-
     def __init__(self, cwd: str, tmpfile: str):
         QObject.__init__(self)
         self.cwd = cwd
@@ -150,15 +152,14 @@ class Helper(QObject):
         msg = QCoreApplication.translate('main', "Built with PySide6 (Qt) v{} and python v{}")
         return msg.format(PySide6_version, sys_version.split("\n")[0])
 
-    @Slot()
+    @Slot(result=PyPromise)
     def fetchChangelog(self):
-        changelog_cache_path = path.join(path.dirname(path.realpath(__file__)), "CHANGELOG.md")
-        if path.exists(changelog_cache_path):
+        """
+        Fetches the changelog and returns a Promise.
+        """
+        if path.exists(CHANGELOG_CACHE_PATH):
             # We have a cached version of the changelog, for env that don't have access to the internet.
-            f = open(changelog_cache_path);
-            self.changelogFetched.emit("".join(f.readlines()).strip())
-            f.close()
+            return PyPromise(read_changelog)
         else:
             # Fetch it from the internet.
-            runnable = ChangelogFetcher(self)
-            QThreadPool.globalInstance().start(runnable)
+            return PyPromise(fetch_changelog)

runtime-pyside6/LogarithmPlotter/util/js.py

@@ -16,13 +16,13 @@
  *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
 """
 from re import Pattern
+from typing import Callable
 from PySide6.QtCore import QMetaObject, QObject, QDateTime
 from PySide6.QtQml import QJSValue
 
 class InvalidAttributeValueException(Exception): pass
 class NotAPrimitiveException(Exception): pass
 
-class Function: pass
 class URL: pass
 
 class PyJSValue:
@@ -78,7 +78,7 @@ class PyJSValue:
         matcher = [
             (lambda: self.qjs_value.isArray(), list),
             (lambda: self.qjs_value.isBool(), bool),
-            (lambda: self.qjs_value.isCallable(), Function),
+            (lambda: self.qjs_value.isCallable(), Callable),
             (lambda: self.qjs_value.isDate(), QDateTime),
             (lambda: self.qjs_value.isError(), Exception),
             (lambda: self.qjs_value.isNull(), None),
@@ -104,3 +104,5 @@ class PyJSValue:
         if self.type() not in [bool, float, str, None]:
             raise NotAPrimitiveException()
         return self.qjs_value.toPrimitive().toVariant()
+
+

runtime-pyside6/LogarithmPlotter/util/latex.py

@@ -15,18 +15,21 @@
  *  You should have received a copy of the GNU General Public License
  *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
 """
+from time import sleep
 
-from PySide6.QtCore import QObject, Slot, Property, QCoreApplication
+from PySide6.QtCore import QObject, Slot, Property, QCoreApplication, Signal
 from PySide6.QtGui import QImage, QColor
 from PySide6.QtWidgets import QMessageBox
 
-from os import path, remove, environ, makedirs
+from os import path, remove, makedirs
 from string import Template
 from subprocess import Popen, TimeoutExpired, PIPE
 from hashlib import sha512
 from shutil import which
 from sys import argv
 
+from LogarithmPlotter.util import config
+from LogarithmPlotter.util.promise import PyPromise
 
 """
 Searches for a valid Latex and DVIPNG (http://savannah.nongnu.org/projects/dvipng/)
@@ -85,6 +88,10 @@ class Latex(QObject):
     def latexSupported(self) -> bool:
         return LATEX_PATH is not None and DVIPNG_PATH is not None
 
+    @Property(bool)
+    def supportsAsyncRender(self) -> bool:
+        return config.getSetting("enable_latex_async")
+
     @Slot(result=bool)
     def checkLatexInstallation(self) -> bool:
         """
@@ -105,13 +112,20 @@ class Latex(QObject):
             valid_install = False
         else:
             try:
-                self.render("", 14, QColor(0, 0, 0, 255))
+                self.renderSync("", 14, QColor(0, 0, 0, 255))
             except MissingPackageException:
                 valid_install = False  # Should have sent an error message if failed to render
         return valid_install
 
+    @Slot(str, float, QColor, result=PyPromise)
+    def renderAsync(self, latex_markup: str, font_size: float, color: QColor) -> PyPromise:
+        """
+        Prepares and renders a latex string into a png file asynchronously.
+        """
+        return PyPromise(self.renderSync, [latex_markup, font_size, color])
+
     @Slot(str, float, QColor, result=str)
-    def render(self, latex_markup: str, font_size: float, color: QColor) -> str:
+    def renderSync(self, latex_markup: str, font_size: float, color: QColor) -> str:
         """
         Prepares and renders a latex string into a png file.
         """
@@ -124,12 +138,14 @@ class Latex(QObject):
             if not path.exists(latex_path + ".dvi"):
                 self.create_latex_doc(latex_path, latex_markup)
                 self.convert_latex_to_dvi(latex_path)
-                self.cleanup(latex_path)
+                # self.cleanup(latex_path)
             # Creating four pictures of different sizes to better handle dpi.
             self.convert_dvi_to_png(latex_path, export_path, font_size, color)
             # self.convert_dvi_to_png(latex_path, export_path+"@2", font_size*2, color)
             # self.convert_dvi_to_png(latex_path, export_path+"@3", font_size*3, color)
             # self.convert_dvi_to_png(latex_path, export_path+"@4", font_size*4, color)
+        else:
+            sleep(0)
         img = QImage(export_path)
         # Small hack, not very optimized since we load the image twice, but you can't pass a QImage to QML and expect it to be loaded
         return f'{export_path}.png,{img.width()},{img.height()}'

runtime-pyside6/LogarithmPlotter/util/promise.py

@@ -0,0 +1,116 @@
+"""
+ *  LogarithmPlotter - 2D plotter software to make BODE plots, sequences and distribution functions.
+ *  Copyright (C) 2021-2024  Ad5001
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+"""
+from typing import Callable
+
+from PySide6.QtCore import QRunnable, Signal, QObject, Slot, QThreadPool
+from PySide6.QtQml import QJSValue
+
+from LogarithmPlotter.util.js import PyJSValue
+
+
+class InvalidReturnValue(Exception): pass
+
+
+class PyPromiseRunner(QRunnable):
+    """
+    QRunnable for running Promises in different threads.
+    """
+    def __init__(self, runner, promise, args):
+        QRunnable.__init__(self)
+        self.runner = runner
+        self.promise = promise
+        self.args = args
+
+    def run(self):
+        try:
+            data = self.runner(*self.args)
+            if isinstance(data, QObject):
+                data = data
+            elif type(data) in [int, str, float, bool, bytes]:
+                data = QJSValue(data)
+            elif data is None:
+                data = QJSValue.SpecialValue.UndefinedValue
+            elif isinstance(data, QJSValue):
+                data = data
+            elif isinstance(data, PyJSValue):
+                data = data.qjs_value
+            else:
+                raise InvalidReturnValue("Must return either a primitive, a valid QObject, JS Value, or None.")
+            self.promise.finished.emit(data)
+        except Exception as e:
+            try:
+                self.promise.errored.emit(repr(e))
+            except RuntimeError as e2:
+                # Happens when the PyPromise has already been garbage collected.
+                # In other words, nothing to report to nowhere.
+                pass
+
+
+class PyPromise(QObject):
+    """
+    Asynchronous Promise-like object meant to interface between Python and Javascript easily.
+    Runs to_run in another thread, and calls fulfilled (populated by then) with its return value.
+    """
+    finished = Signal((QJSValue,), (QObject,))
+    errored = Signal(Exception)
+
+    def __init__(self, to_run: Callable, args):
+        QObject.__init__(self)
+        self._fulfills = []
+        self._rejects = []
+        self.finished.connect(self._fulfill)
+        self.errored.connect(self._reject)
+        self._runner = PyPromiseRunner(to_run, self, args)
+        QThreadPool.globalInstance().start(self._runner)
+
+
+    @Slot(QJSValue, result=QObject)
+    @Slot(QJSValue, QJSValue, result=QObject)
+    def then(self, on_fulfill: QJSValue | Callable, on_reject: QJSValue | Callable = None):
+        """
+        Adds listeners for both fulfilment and catching errors of the Promise.
+        """
+        if isinstance(on_fulfill, QJSValue):
+            self._fulfills.append(PyJSValue(on_fulfill))
+        elif isinstance(on_fulfill, Callable):
+            self._fulfills.append(on_fulfill)
+        if isinstance(on_reject, QJSValue):
+            self._rejects.append(PyJSValue(on_reject))
+        elif isinstance(on_reject, Callable):
+            self._rejects.append(on_reject)
+        return self
+
+    @Slot(QJSValue)
+    @Slot(QObject)
+    def _fulfill(self, data):
+        no_return = [None, QJSValue.SpecialValue.UndefinedValue]
+        for on_fulfill in self._fulfills:
+            try:
+                result = on_fulfill(data)
+                data = result if result not in no_return else data  # Forward data.
+            except Exception as e:
+                self._reject(repr(e))
+                break
+
+    @Slot(QJSValue)
+    @Slot(str)
+    def _reject(self, error):
+        no_return = [None, QJSValue.SpecialValue.UndefinedValue]
+        for on_reject in self._rejects:
+            result = on_reject(error)
+            error = result if result not in no_return else error  # Forward data.