wizard no longer crashes if selection menu reloaded

wizard now caches icons so no duplication of requests
enforcement of dependencies partially implemented
allowed redirection of all network requests

portable_computing_toolkit_installer/ui/installer_wizard.py

@@ -34,6 +34,7 @@ class InstallerWizard(QtWidgets.QWizard):
         self.selection_page.initializePage = self._load_tools
         self.intro.anchorClicked.connect(self._link_clicked)
         self.license.anchorClicked.connect(self._link_clicked)
+        self.selection_menu.itemClicked.connect(self._enforce_dependencies)
         self.install_location.setValidator(Location_Validator(parent=self))
         self.location_page.registerField("Location*", self.install_location)
         self.browse_button.clicked.connect(self._select_location)
@@ -95,6 +96,7 @@ class InstallerWizard(QtWidgets.QWizard):
         if self._network_manager.networkAccessible():
             request = QtNetwork.QNetworkRequest(QtCore.QUrl("https://www.gnu.org/licenses/gpl-3.0-standalone.html"))
             request.setAttribute(QtNetwork.QNetworkRequest.CacheLoadControlAttribute, QtNetwork.QNetworkRequest.AlwaysNetwork)
+            request.setAttribute(QtNetwork.QNetworkRequest.FollowRedirectsAttribute, True)
             reply = self._network_manager.get(request)
             reply.downloadProgress.connect(lambda received, total: process_dialog.setMaximum(total))
             reply.downloadProgress.connect(lambda received, total: process_dialog.setValue(received))
@@ -147,8 +149,15 @@ class InstallerWizard(QtWidgets.QWizard):
         process_dialog.setAutoClose(True)
         process_dialog.setAutoReset(True)
         process_dialog.setCancelButton(None)
+        try: #clear data from this page before reloading
+            self.__tools__ = None
+            self._icon_cache = {item.text(0):item.icon(0) for item in list(MenuIterator(self.selection_menu, QtWidgets.QTreeWidgetItemIterator.NoChildren))}
+            self.selection_menu.clear()
+        except NameError:
+            pass
         request = QtNetwork.QNetworkRequest(QtCore.QUrl("https://raw.githubusercontent.com/norweeg/portable-computing-toolkit-installer/initial_dev/portable_computing_toolkit_installer/resources/supported_tools.json"))
         request.setAttribute(QtNetwork.QNetworkRequest.CacheLoadControlAttribute, QtNetwork.QNetworkRequest.AlwaysNetwork)
+        request.setAttribute(QtNetwork.QNetworkRequest.FollowRedirectsAttribute, True)
         reply = self._network_manager.get(request)
         reply.downloadProgress.connect(lambda received, total: process_dialog.setMaximum(total))
         reply.downloadProgress.connect(lambda received, total: process_dialog.setValue(received))
@@ -163,7 +172,6 @@ class InstallerWizard(QtWidgets.QWizard):
                 self._display_error(f"Unable to decode {request.url.toString()}", e).accepted.connect(self.back)
             else:
                 self._populate_menu()
-                self.selection_menu.itemSelectionChanged.connect(self._enforce_dependencies)
         else:
             self._display_error(f"Encountered an error while loading supported tools from {request.url().toString()}", reply.errorString()).finished.connect(lambda x: self.back())
 
@@ -201,6 +209,9 @@ class InstallerWizard(QtWidgets.QWizard):
                 new_item.setFlags(new_item.flags()|QtCore.Qt.ItemNeverHasChildren)
                 new_item.setData(1, QtCore.Qt.DecorationRole, QtGui.QIcon(str(Path(__file__).parent.parent/"resources/icons/internet-web-browser-4.png")))
                 new_item.setData(1, QtCore.Qt.ToolTipRole, tool["homepage"])
+                try:
+                    new_item.setIcon(0, self._icon_cache[new_item.text(0)])
+                except (AttributeError, KeyError):
                     try:
                         self._get_icon(new_item, tool["icon url"])
                     except KeyError:
@@ -244,20 +255,24 @@ class InstallerWizard(QtWidgets.QWizard):
         """
         if not icon_url:
             icon_url = QtCore.QUrl(f"http://www.google.com/s2/favicons?domain={QtCore.QUrl(tree_item.data(1, QtCore.Qt.ToolTipRole)).toString()}")
-        icon_request = self._network_manager.get(QtNetwork.QNetworkRequest(QtCore.QUrl(icon_url)))
+        icon_request = QtNetwork.QNetworkRequest(QtCore.QUrl(icon_url))
+        icon_request.setAttribute(QtNetwork.QNetworkRequest.CacheLoadControlAttribute, QtNetwork.QNetworkRequest.AlwaysNetwork)
+        icon_request.setAttribute(QtNetwork.QNetworkRequest.FollowRedirectsAttribute, True)
+        icon_reply = self._network_manager.get(icon_request)
         #when download is complete, validates request returned without error and sets icon
-        icon_request.finished.connect(partial(self._set_icon, tree_item, icon_request))
+        icon_reply.finished.connect(partial(self._set_icon, tree_item, icon_reply))
+        icon_reply.error.connect(lambda error: self._display_error(QtCore.QMetaEnum.valueToKey(error)))
 
-    def _set_icon(self, tree_item, request):
+    def _set_icon(self, tree_item, reply):
         """Validates a network request and sets its result as the icon of a QTreeWidgetItem.
 
         Arguments:
             tree_item {QTreeWidgetItem} -- A tree widget item to set the icon of
             request {QNetworkReply} -- The results of the HTTP GET request whose data will be used as the icon for tree_item
         """
-        if not request.error():
+        if not reply.error():
             pixmap = QtGui.QPixmap()
-            pixmap.loadFromData(request.readAll())
+            pixmap.loadFromData(reply.readAll())
             tree_item.setIcon(0, QtGui.QIcon(pixmap))
 
     def _get_selections(self):
@@ -265,15 +280,17 @@ class InstallerWizard(QtWidgets.QWizard):
         """
         return list(MenuIterator(self.selection_menu, QtWidgets.QTreeWidgetItemIterator.Checked|QtWidgets.QTreeWidgetItemIterator.NoChildren))
 
-    @QtCore.pyqtSlot()
+    @QtCore.pyqtSlot("QTreeWidgetItem*","int")
-    def _enforce_dependencies(self):
+    def _enforce_dependencies(self, item, column):
-        for tool in self._get_selections():
+        #if item is checked, look for dependent items and check them too
+        if item.checkState(0) == QtCore.Qt.Checked:
+            tools_by_name = {tool["name"]:tool for tool in self.__tools__}
             try:
-                dependencies = tool["depends on"].split(",")
+                dependencies = tools_by_name[item.text(0)]["depends on"].split(",")
             except KeyError:
-                continue
+                pass
             else:
-                for dependency in [self.selection_menu.findItems(item, QtCore.Qt.MatchFixedString|QtCore.Qt.MatchCaseSensitive|QtCore.Qt.MatchRecursive) for item in dependencies]:
+                for dependency in dependencies:
-                    dependency.setSelected(True)
+                    for dependant_item in self.selection_menu.findItems(dependency, QtCore.Qt.MatchFixedString|QtCore.Qt.MatchCaseSensitive|QtCore.Qt.MatchRecursive):
-                    dependency.setHidden(False)
+                        dependant_item.setCheckState(0, QtCore.Qt.Checked)