Prevent UI flicker on conversation switch / update

Makefile

@@ -3,11 +3,11 @@ SHELL := /bin/bash
 
 .PHONY: clean
 clean:  ## Clean the workspace of generated resources
-	@rm -rf build dist *.egg-info .coverage .eggs docs/_build .pytest_cache lib htmlcov && \
+	@rm -rf build dist *.egg-info .coverage .eggs docs/_build .pytest_cache lib htmlcov .cache && \
 		find . \( -name '*.py[co]' -o -name dropin.cache \) -delete && \
 		find . \( -name '*.bak' -o -name dropin.cache \) -delete && \
 		find . \( -name '*.tgz' -o -name dropin.cache \) -delete && \
-		find . -name __pycache__ -print0 | xargs rm -rf
+		find . -name __pycache__ -print0 | xargs -0 rm -rf
 
 TESTS ?= tests
 TESTOPTS ?= -v
@@ -34,7 +34,7 @@ check: clean lint test ## Run the full CI test suite
 # 6. Format columns with colon as delimiter.
 .PHONY: help
 help: ## Print this message and exit.
-	@printf "Makefile for developing and testing SecureDrop.\n"
+	@printf "Makefile for developing and testing the SecureDrop client.\n"
 	@printf "Subcommands:\n\n"
 	@awk 'BEGIN {FS = ":.*?## "} /^[0-9a-zA-Z_-]+:.*?## / {printf "\033[36m%s\033[0m : %s\n", $$1, $$2}' $(MAKEFILE_LIST) \
 		| sort \

run.sh

@@ -26,9 +26,11 @@ chmod 0700 "$SDC_HOME" "$GPG_HOME"
 echo "Running app with home directory: $SDC_HOME"
 echo ""
 
-gpg --homedir "$GPG_HOME" --allow-secret-key-import --import tests/files/securedrop.gpg.asc
+gpg --homedir "$GPG_HOME" --allow-secret-key-import --import tests/files/securedrop.gpg.asc &
 
 # create the database and config for local testing
-./create_dev_data.py "$SDC_HOME"
+./create_dev_data.py "$SDC_HOME" &
+
+wait
 
 exec python -m securedrop_client --sdc-home "$SDC_HOME" --no-proxy $@

securedrop_client/app.py

@@ -65,16 +65,19 @@ def configure_logging(sdc_home: str) -> None:
     log_fmt = ('%(asctime)s - %(name)s:%(lineno)d(%(funcName)s) '
                '%(levelname)s: %(message)s')
     formatter = logging.Formatter(log_fmt)
+
     # define log handlers such as for rotating log files
     handler = TimedRotatingFileHandler(log_file, when='midnight',
                                        backupCount=5, delay=0,
                                        encoding=ENCODING)
     handler.setFormatter(formatter)
     handler.setLevel(logging.DEBUG)
+
     # set up primary log
     log = logging.getLogger()
     log.setLevel(logging.DEBUG)
     log.addHandler(handler)
+
     # override excepthook to capture a log of catastrophic failures.
     sys.excepthook = excepthook
 

securedrop_client/db.py

@@ -25,7 +25,9 @@ def make_engine(home: str):
 
 
 class Source(Base):
+
     __tablename__ = 'sources'
+
     # TODO - add number_of_docs
     id = Column(Integer, primary_key=True)
     uuid = Column(String(36), unique=True, nullable=False)
@@ -66,7 +68,9 @@ def collection(self):
 
 
 class Submission(Base):
+
     __tablename__ = 'submissions'
+
     id = Column(Integer, primary_key=True)
     uuid = Column(String(36), unique=True, nullable=False)
     filename = Column(String(255), nullable=False)
@@ -101,7 +105,9 @@ def __repr__(self):
 
 
 class Reply(Base):
+
     __tablename__ = 'replies'
+
     id = Column(Integer, primary_key=True)
     uuid = Column(String(36), unique=True, nullable=False)
     source_id = Column(Integer, ForeignKey('sources.id'))
@@ -133,7 +139,9 @@ def __repr__(self):
 
 
 class User(Base):
+
     __tablename__ = 'users'
+
     id = Column(Integer, primary_key=True)
     uuid = Column(String(36), unique=True, nullable=False)
     username = Column(String(255), nullable=False, unique=True)

securedrop_client/gui/main.py

@@ -23,10 +23,8 @@
 from PyQt5.QtWidgets import QMainWindow, QWidget, QVBoxLayout, QDesktopWidget, QStatusBar
 from securedrop_client import __version__
 from securedrop_client.gui.widgets import (ToolBar, MainView, LoginDialog,
-                                           ConversationView,
-                                           SourceProfileShortWidget)
+                                           SourceConversationWrapper)
 from securedrop_client.resources import load_icon
-from securedrop_client.storage import get_data
 
 logger = logging.getLogger(__name__)
 
@@ -53,19 +51,29 @@ def __init__(self, sdc_home: str):
         self.sdc_home = sdc_home
         self.setWindowTitle(_("SecureDrop Client {}").format(__version__))
         self.setWindowIcon(load_icon(self.icon))
+
         self.widget = QWidget()
         widget_layout = QVBoxLayout()
         self.widget.setLayout(widget_layout)
+        self.setCentralWidget(self.widget)
+
         self.tool_bar = ToolBar(self.widget)
+
         self.main_view = MainView(self.widget)
         self.main_view.source_list.itemSelectionChanged.connect(self.on_source_changed)
+
         widget_layout.addWidget(self.tool_bar, 1)
         widget_layout.addWidget(self.main_view, 6)
-        self.setCentralWidget(self.widget)
-        self.current_source = None  # Tracks which source is shown
+
+        # Cache a dict of source.uuid -> SourceConversationWrapper
+        # We do this to not create/destroy widgets constantly (because it causes UI "flicker")
         self.conversations = {}
-        self.show()
+
+        # Tracks which source is shown
+        self.current_source = None
+
         self.autosize_window()
+        self.show()
 
     def setup(self, controller):
         """
@@ -74,9 +82,11 @@ def setup(self, controller):
         """
         self.controller = controller  # Reference the Client logic instance.
         self.tool_bar.setup(self, controller)
+
         self.status_bar = QStatusBar(self)
         self.setStatusBar(self.status_bar)
         self.set_status('Started SecureDrop Client. Please sign in.', 20000)
+
         self.login_dialog = LoginDialog(self)
         self.main_view.setup(self.controller)
 
@@ -156,47 +166,21 @@ def on_source_changed(self):
             self.current_source = source_widget.source
             self.show_conversation_for(self.current_source)
 
-    def add_item_content_or(self, adder, item, default):
-        """
-        Private helper function to add correct message to conversation widgets
-        """
-        if item.is_downloaded is False:
-            adder(default)
-        else:
-            adder(get_data(self.sdc_home, item.filename))
-
     def show_conversation_for(self, source):
         """
         Show conversation of messages and replies between a source and
         journalists.
         """
-        conversation = ConversationView(self)
-        conversation.setup(self.controller)
-        conversation.add_message('Source name: {}'.format(
-                                 source.journalist_designation))
-
-        # Display each conversation item in the source collection.
-        for conversation_item in source.collection:
-
-            if conversation_item.filename.endswith('msg.gpg'):
-                self.add_item_content_or(conversation.add_message,
-                                         conversation_item,
-                                         "<Message not yet downloaded>")
-            elif conversation_item.filename.endswith('reply.gpg'):
-                self.add_item_content_or(conversation.add_reply,
-                                         conversation_item,
-                                         "<Reply not yet downloaded>")
-            else:
-                conversation.add_file(source, conversation_item)
-
-        container = QWidget()
-        layout = QVBoxLayout()
-        container.setLayout(layout)
-        source_profile = SourceProfileShortWidget(source, self.controller)
-
-        layout.addWidget(source_profile)
-        layout.addWidget(conversation)
-        self.main_view.update_view(container)
+
+        conversation_container = self.conversations.get(source.uuid, None)
+
+        if conversation_container is None:
+            conversation_container = SourceConversationWrapper(source,
+                                                               self.sdc_home,
+                                                               self.controller)
+            self.conversations[source.uuid] = conversation_container
+
+        self.main_view.set_conversation(conversation_container)
 
     def set_status(self, message, duration=5000):
         """