Addon Manager: Replace QtWebEngine with QTextBrowser

Macro display is still a work-in-progress.

src/Mod/AddonManager/CMakeLists.txt

@@ -28,6 +28,7 @@ SET(AddonManager_SRCS
     addonmanager_macro_parser.py
     addonmanager_metadata.py
     addonmanager_pyside_interface.py
+    addonmanager_readme_viewer.py
     addonmanager_update_all_gui.py
     addonmanager_uninstaller.py
     addonmanager_uninstaller_gui.py

src/Mod/AddonManager/addonmanager_readme_viewer.py

@@ -0,0 +1,119 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+# ***************************************************************************
+# *                                                                         *
+# *   Copyright (c) 2024 The FreeCAD Project Association AISBL              *
+# *                                                                         *
+# *   This file is part of FreeCAD.                                         *
+# *                                                                         *
+# *   FreeCAD is free software: you can redistribute it and/or modify it    *
+# *   under the terms of the GNU Lesser General Public License as           *
+# *   published by the Free Software Foundation, either version 2.1 of the  *
+# *   License, or (at your option) any later version.                       *
+# *                                                                         *
+# *   FreeCAD 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      *
+# *   Lesser General Public License for more details.                       *
+# *                                                                         *
+# *   You should have received a copy of the GNU Lesser General Public      *
+# *   License along with FreeCAD. If not, see                               *
+# *   <https://www.gnu.org/licenses/>.                                      *
+# *                                                                         *
+# ***************************************************************************
+
+""" A Qt Widget for displaying Addon README information """
+
+import Addon
+from PySide import QtCore, QtGui, QtWidgets
+
+import addonmanager_freecad_interface as fci
+import addonmanager_utilities as utils
+import NetworkManager
+
+translate = fci.translate
+
+
+class ReadmeViewer(QtWidgets.QTextBrowser):
+
+    """A QTextBrowser widget that, when given an Addon, downloads the README data as appropriate
+    and renders it with whatever technology is available (usually Qt's Markdown renderer for
+    workbenches and its HTML renderer for Macros)."""
+
+    def __init__(self, parent=None):
+        super().__init__(parent)
+        NetworkManager.InitializeNetworkManager()
+        NetworkManager.AM_NETWORK_MANAGER.completed.connect(self._download_completed)
+        self.request_index = 0
+        self.url = ""
+        self.repo: Addon.Addon = None
+        self.setOpenExternalLinks(True)
+        self.setOpenLinks(True)
+        self.image_map = {}
+
+    def set_addon(self, repo: Addon):
+        """Set which Addon's information is displayed"""
+
+        self.setPlainText(translate("AddonsInstaller", "Loading README data..."))
+        self.repo = repo
+        if self.repo.repo_type == Addon.Addon.Kind.MACRO:
+            self.url = self.repo.macro.wiki
+            if not self.url:
+                self.url = self.repo.macro.url
+        else:
+            self.url = utils.get_readme_url(repo)
+
+        self.request_index = NetworkManager.AM_NETWORK_MANAGER.submit_unmonitored_get(self.url)
+
+    def _download_completed(self, index: int, code: int, data: QtCore.QByteArray) -> None:
+        """Callback for handling a completed README file download."""
+        if index == self.request_index:
+            if code == 200:  # HTTP success
+                self._process_package_download(data.data().decode("utf-8"))
+            else:
+                self.setPlainText(
+                    translate(
+                        "AddonsInstaller",
+                        "Failed to download data from {} -- received response code {}.",
+                    ).format(self.url, code)
+                )
+
+    def _process_package_download(self, data: str):
+        if self.repo.repo_type == Addon.Addon.Kind.MACRO:
+            self.setHtml(data)
+        else:
+            if hasattr(self, "setMarkdown"):
+                self.setMarkdown(data)
+            else:
+                self.setPlainText(data)
+
+    def loadResource(self, resource_type: int, name: QtCore.QUrl) -> object:
+        """Callback for resource loading. Called automatically by underlying Qt
+        code when external resources are needed for rendering. In particular,
+        here it is used to download and cache (in RAM) the images needed for the
+        README and Wiki pages."""
+        if resource_type == QtGui.QTextDocument.ImageResource:
+            full_url = self._create_full_url(name.toString())
+            if full_url not in self.image_map:
+                self.image_map[full_url] = None
+                fci.Console.PrintMessage(f"Downloading image from {full_url}...\n")
+                data = NetworkManager.AM_NETWORK_MANAGER.blocking_get(full_url)
+                if data and data.data():
+                    image = QtGui.QImage.fromData(data.data())
+                    if image:
+                        self.image_map[full_url] = self._ensure_appropriate_width(image)
+            return self.image_map[full_url]
+        return super().loadResource(resource_type, name)
+
+    def _create_full_url(self, url: str) -> str:
+        if url.startswith("http"):
+            return url
+        if not self.url:
+            return url
+        lhs, slash, _ = self.url.rpartition("/")
+        return lhs + slash + url
+
+    def _ensure_appropriate_width(self, image: QtGui.QImage) -> QtGui.QImage:
+        ninety_seven_percent = self.width() * 0.97
+        if image.width() < ninety_seven_percent:
+            return image
+        return image.scaledToWidth(ninety_seven_percent)