Removed dependency on Sympy for subprocesses directly.

New dependencies: latex, dvipng.

Slight changes to default for fonts to avoid too many anti aliasing issues.
Also adds proper checks for latex installation.

LogarithmPlotter/logarithmplotter.py

@@ -18,8 +18,6 @@
 
 from time import time
 
-start_time = time()
-
 from PySide2.QtWidgets import QApplication
 from PySide2.QtQml import QQmlApplicationEngine
 from PySide2.QtCore import Qt, QTranslator, QLocale
@@ -29,6 +27,9 @@ from tempfile import TemporaryDirectory
 from os import getcwd, chdir, environ, path, remove, close
 from platform import release as os_release
 from sys import platform, argv, version as sys_version, exit
+from sys import path as sys_path
+
+start_time = time()
 
 # Create the temporary directory for saving copied screenshots and latex files
 tempdir = TemporaryDirectory()
@@ -37,7 +38,6 @@ pwd = getcwd()
 
 chdir(path.dirname(path.realpath(__file__)))
 
-from sys import path as sys_path
 if path.realpath(path.join(getcwd(), "..")) not in sys_path:
     sys_path.append(path.realpath(path.join(getcwd(), "..")))
 
@@ -85,11 +85,11 @@ def run():
     icon_fallbacks.append(path.realpath(path.join(base_icon_path, "settings", "custom")))
     QIcon.setFallbackSearchPaths(icon_fallbacks);
     
+    QApplication.setAttribute(Qt.AA_EnableHighDpiScaling) 
     app = QApplication(argv)
     app.setApplicationName("LogarithmPlotter")
     app.setOrganizationName("Ad5001")
     app.styleHints().setShowShortcutsInContextMenus(True)
-    app.setAttribute(Qt.AA_EnableHighDpiScaling) 
     app.setWindowIcon(QIcon(path.realpath(path.join(getcwd(), "logarithmplotter.svg"))))
     
     # Installing translators
@@ -109,7 +109,7 @@ def run():
     engine = QQmlApplicationEngine()
     global tmpfile
     helper = Helper(pwd, tmpfile)
-    latex = Latex(tempdir, app.palette())
+    latex = Latex(tempdir)
     engine.rootContext().setContextProperty("Helper", helper)
     engine.rootContext().setContextProperty("Latex", latex)
     engine.rootContext().setContextProperty("TestBuild", "--test-build" in argv)
@@ -135,6 +135,8 @@ def run():
     if platform == "darwin":
         macOSFileOpenHandler.init_graphics(engine.rootObjects()[0])
     
+    latex.check_latex_install()
+    
     # Check for updates
     if config.getSetting("check_for_updates"):
         check_for_updates(__VERSION__, engine.rootObjects()[0])

LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/LogGraphCanvas.qml

@@ -200,7 +200,7 @@ Canvas {
         // Reset
         ctx.fillStyle = "#FFFFFF"
         ctx.strokeStyle = "#000000"
-        ctx.font = `${canvas.textsize-2}px sans-serif`
+        ctx.font = `${canvas.textsize}px sans-serif`
         ctx.fillRect(0,0,width,height)
     }
     
@@ -257,12 +257,12 @@ Canvas {
         var axisxpx = y2px(0) // Y coordinate of X axis
         // Labels
         ctx.fillStyle = "#000000"
-        ctx.font = `${canvas.textsize+2}px sans-serif`
+        ctx.font = `${canvas.textsize}px sans-serif`
         ctx.fillText(ylabel, axisypx+10, 24)
         var textSize = ctx.measureText(xlabel).width
         ctx.fillText(xlabel, canvasSize.width-14-textSize, axisxpx-5)
         // Axis graduation labels
-        ctx.font = `${canvas.textsize-2}px sans-serif`
+        ctx.font = `${canvas.textsize-4}px sans-serif`
         
         var txtMinus = ctx.measureText('-').width
         if(showxgrad) {

LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/Settings.qml

@@ -99,7 +99,7 @@ ScrollView {
        Font size of the text that will be drawn into the canvas, provided from settings.
        \sa Settings
     */
-    property double textsize: 14
+    property double textsize: 18
     /*!
        \qmlproperty bool Settings::logscalex
        true if the canvas should be in logarithmic mode, false otherwise.

LogarithmPlotter/util/latex.py

@@ -16,23 +16,156 @@
  *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
 """
 
-from PySide2.QtCore import QObject, Slot
+from PySide2.QtCore import QObject, Slot, Property, QCoreApplication
 from PySide2.QtGui import QImage, QColor
-from PySide2.QtWidgets import QApplication
+from PySide2.QtWidgets import QApplication, QMessageBox
 
-from os import path
+from os import path, remove
-from sympy import preview
+from string import Template
 from tempfile import TemporaryDirectory
+from subprocess import Popen, TimeoutExpired, PIPE
+from platform import system
+from shutil import which
+
+"""
+Searches for a valid Latex and DVIPNG (http://savannah.nongnu.org/projects/dvipng/)
+installation and collects the binary path in the DVIPNG_PATH variable.
+If not found, it will send an alert to the user.
+"""
+LATEX_PATH = which('latex')
+DVIPNG_PATH = which('dvipng')
+#subprocess.run(["ls", "-l", "/dev/null"], capture_output=True)
+
+DEFAULT_LATEX_DOC = Template(r"""
+\documentclass[]{minimal}
+\usepackage[utf8]{inputenc}
+\usepackage{calligra}
+\usepackage{amsfonts}
+
+\title{}
+\author{}
+
+\begin{document}
+
+$$$$ $markup $$$$
+
+\end{document}
+""")
     
 class Latex(QObject):
-    def __init__(self, tempdir: str, palette):
+    """
+    Base class to convert Latex equations into PNG images with custom font color and size.
+    It doesn't have any python dependency, but requires a working latex installation and
+    dvipng to be installed on the system.
+    """
+    def __init__(self, tempdir: TemporaryDirectory):
         QObject.__init__(self)
         self.tempdir = tempdir
-        self.palette = palette
+    
-        fg = self.palette.windowText().color().convertTo(QColor.Rgb)
+    def check_latex_install(self):
+        """
+        Checks if the current latex installation is valid.
+        """
+        if LATEX_PATH is None:
+            QMessageBox.warning(None, "LogarithmPlotter - Latex setup", QCoreApplication.translate("latex", "No Latex installation found.\nIf you already have a latex distribution installed, make sure it's installed on your path.\nOtherwise, you can download a Latex distribution like TeX Live at https://tug.org/texlive/."))
+        elif DVIPNG_PATH is None:
+            QMessageBox.warning(None, "LogarithmPlotter - Latex setup", QCoreApplication.translate("latex", "DVIPNG was not found. Make sure you include it from your Latex distribution."))    
+    
+    @Property(bool)
+    def latexSupported(self):
+        return LATEX_PATH is not None and DVIPNG_PATH is not None
         
     @Slot(str, float, QColor, result=str)
-    def render(self, latexstring, font_size, color = True):
+    def render(self, latex_markup: str, font_size: float, color: QColor = True) -> str:
+        """
+        Renders a latex string into a png file.
+        """
+        export_path = path.join(self.tempdir.name, f'{hash(latex_markup)}_{font_size}_{color.rgb()}')
+        print(export_path)
+        if self.latexSupported and not path.exists(export_path + ".png"):
+            # Generating file
+            try:
+                self.create_latex_doc(export_path, latex_markup)
+                self.convert_latex_to_dvi(export_path)
+                self.convert_dvi_to_png(export_path, font_size, color)
+                self.cleanup(export_path)
+            except Exception as e: # One of the processes failed. A message will be sent every time.
+                raise e
+        img = QImage(export_path + ".png");
+        # 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()}'
+        
+    def create_latex_doc(self, export_path: str, latex_markup: str):
+        """
+        Creates a temporary latex document with base file_hash as file name and a given expression markup latex_markup.
+        """
+        ltx_path = export_path + ".tex"
+        f = open(export_path + ".tex", 'w')
+        f.write(DEFAULT_LATEX_DOC.substitute(markup = latex_markup))
+        f.close()
+    
+    def convert_latex_to_dvi(self, export_path: str):
+        """
+        Converts a DVI file to a PNG file.
+        """
+        self.run([
+            LATEX_PATH,
+            export_path + ".tex"
+        ])
+        
+    
+    def convert_dvi_to_png(self, export_path: str, font_size: float, color: QColor):
+        """
+        Converts a DVI file to a PNG file.
+        Documentation: https://linux.die.net/man/1/dvipng
+        """
+        fg = color.convertTo(QColor.Rgb)
+        fg = f'rgb {fg.redF()} {fg.greenF()} {fg.blueF()}'
+        depth = int(font_size * 72.27 / 100) * 10
+        self.run([
+            DVIPNG_PATH,
+            '-T', 'tight',              # Make sure image borders are as tight around the equation as possible to avoid blank space.
+            '--truecolor',              # Make sure it's rendered in 24 bit colors.
+            '-D',f'{depth}',            # Depth of the image
+            '-bg', 'Transparent',       # Transparent background
+            '-fg',f'{fg}',              # Foreground of the wanted color.
+            f'{export_path}.dvi',       # Input file
+            '-o',f'{export_path}.png',  # Output file
+        ])
+    
+    def run(self, process: list):
+        """
+        Runs a subprocess and handles exceptions and messages them to the user.
+        """
+        proc = Popen(process, stdout=PIPE, stderr=PIPE, cwd=self.tempdir.name)
+        try:
+            out, err = proc.communicate(timeout=5) # 5 seconds is already FAR too long.
+            if proc.returncode != 0:
+                # Process errored
+                QMessageBox.warning(None, "LogarithmPlotter - Latex", 
+                                QCoreApplication.translate("latex", "An exception occured within the creation of the latex formula.\nProcess '{}' ended with a non-zero return code {}:\n{}\nPlease make sure your latex installation is correct and report a bug if so.")
+                                .format(" ".join(process), proc.returncode, str(out, 'utf8')+"\n"+str(err,'utf8')))
+                raise Exception(" ".join(process) + " process exited with return code " + str(proc.returncode) + ":\n" + str(out, 'utf8')+"\n"+str(err,'utf8'))
+            print(out)
+        except TimeoutExpired as e:
+            # Process timed out
+            proc.kill()
+            out, err = proc.communicate()
+            QMessageBox.warning(None, "LogarithmPlotter - Latex",
+                                QCoreApplication.translate("latex", "An exception occured within the creation of the latex formula.\nProcess '{}' took too long to finish:\n{}\nPlease make sure your latex installation is correct and report a bug if so.")
+                                    .format(" ".join(process), str(out, 'utf8')+"\n"+str(err,'utf8')))
+            raise Exception(" ".join(process) + " process timed out:\n" + str(out, 'utf8')+"\n"+str(err,'utf8'))
+    
+    def cleanup(self, export_path): 
+        """
+        Removes Tex, auxiliary, logs and DVI temporary files.
+        """
+        for i in [".tex", ".dvi", ".aux", ".log"]:
+            remove(export_path + i)
+        
+        
+    @Slot(str, float, QColor, result=str)
+    def render_legacy(self, latexstring, font_size, color = True):
         exprpath = path.join(self.tempdir.name, f'{hash(latexstring)}_{font_size}_{color.rgb()}.png')
         print("Rendering", latexstring, exprpath)
         if not path.exists(exprpath):
@@ -49,9 +182,3 @@ class Latex(QObject):
         img = QImage(exprpath);
         # 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'{exprpath},{img.width()},{img.height()}'
-    
-    @Slot(str)
-    def copyLatexImageToClipboard(self, latexstring):
-        global tempfile
-        clipboard = QApplication.clipboard()
-        clipboard.setImage(self.render(latexstring))

linux/debian/control

@@ -3,7 +3,7 @@ Source: logarithmplotter
 Version: 0.1.9
 Architecture: all
 Maintainer: Ad5001 <mail@ad5001.eu>
-Depends: python3, python3-pip, qml-module-qtquick-controls2 (>= 5.12.0), qml-module-qtmultimedia (>= 5.12.0), qml-module-qtgraphicaleffects (>= 5.12.0), qml-module-qtquick2 (>= 5.12.0), qml-module-qtqml-models2 (>= 5.12.0), qml-module-qtquick-controls (>= 5.12.0), python3-pyside2.qtcore (>= 5.12.0), python3-pyside2.qtqml (>= 5.12.0), python3-pyside2.qtgui (>= 5.12.0), python3-pyside2.qtquick (>= 5.12.0), python3-pyside2.qtwidgets (>= 5.12.0), python3-pyside2.qtmultimedia (>= 5.12.0), python3-pyside2.qtnetwork (>= 5.12.0), python3-sympy
+Depends: python3, python3-pip, qml-module-qtquick-controls2 (>= 5.12.0), qml-module-qtmultimedia (>= 5.12.0), qml-module-qtgraphicaleffects (>= 5.12.0), qml-module-qtquick2 (>= 5.12.0), qml-module-qtqml-models2 (>= 5.12.0), qml-module-qtquick-controls (>= 5.12.0), python3-pyside2.qtcore (>= 5.12.0), python3-pyside2.qtqml (>= 5.12.0), python3-pyside2.qtgui (>= 5.12.0), python3-pyside2.qtquick (>= 5.12.0), python3-pyside2.qtwidgets (>= 5.12.0), python3-pyside2.qtmultimedia (>= 5.12.0), python3-pyside2.qtnetwork (>= 5.12.0), texlive-latex-base, dvipng
 
 Build-Depends: debhelper (>=11~), dh-python, dpkg-dev (>= 1.16.1~), python-setuptools, python3-all-dev (>=3.6)
 Section: science

linux/debian/depends

@@ -1 +1 @@
-python3-pip, qml-module-qtquick-controls2 (>= 5.12.0), qml-module-qtmultimedia (>= 5.12.0), qml-module-qtgraphicaleffects (>= 5.12.0), qml-module-qtquick2 (>= 5.12.0), qml-module-qtqml-models2 (>= 5.12.0), qml-module-qtquick-controls (>= 5.12.0), python3-pyside2.qtcore (>= 5.12.0), python3-pyside2.qtqml (>= 5.12.0), python3-pyside2.qtgui (>= 5.12.0), python3-pyside2.qtquick (>= 5.12.0), python3-pyside2.qtwidgets (>= 5.12.0), python3-pyside2.qtmultimedia (>= 5.12.0), python3-pyside2.qtnetwork (>= 5.12.0), python3-sympy
+python3-pip, qml-module-qtquick-controls2 (>= 5.12.0), qml-module-qtmultimedia (>= 5.12.0), qml-module-qtgraphicaleffects (>= 5.12.0), qml-module-qtquick2 (>= 5.12.0), qml-module-qtqml-models2 (>= 5.12.0), qml-module-qtquick-controls (>= 5.12.0), python3-pyside2.qtcore (>= 5.12.0), python3-pyside2.qtqml (>= 5.12.0), python3-pyside2.qtgui (>= 5.12.0), python3-pyside2.qtquick (>= 5.12.0), python3-pyside2.qtwidgets (>= 5.12.0), python3-pyside2.qtmultimedia (>= 5.12.0), python3-pyside2.qtnetwork (>= 5.12.0), texlive-latex-base, dvipng

setup.py

@@ -127,7 +127,7 @@ if sys.platform == 'linux':
             os.remove(os.environ["PREFIX"] + '/icons/hicolor/scalable/apps/logplotter.svg')
 
 setuptools.setup(
-    install_requires=([] if "FLATPAK_INSTALL" in os.environ else ["PySide2", "sympy"]),
+    install_requires=([] if "FLATPAK_INSTALL" in os.environ else ["PySide2"]),
     python_requires='>=3.8',
 
     name='logarithmplotter',