Fix regressions regarding UI resizing

The room list would be hidden only through window resizing.

include/ChatPage.h

@@ -69,6 +69,14 @@ public:
         QSharedPointer<UserSettings> userSettings() { return userSettings_; }
         void deleteConfigs();
 
+        //! Calculate the width of the message timeline.
+        int timelineWidth();
+        bool isSideBarExpanded();
+        //! Hide the room & group list (if it was visible).
+        void hideSideBars();
+        //! Show the room/group list (if it was visible).
+        void showSideBars();
+
 public slots:
         void leaveRoom(const QString &room_id);
 

include/Config.h

@@ -8,6 +8,7 @@
 // Font sizes are in pixels.
 
 namespace conf {
+constexpr int sideBarCollapsePoint = 450;
 // Global settings.
 constexpr int fontSize                   = 14;
 constexpr int textInputFontSize          = 14;

include/MainWindow.h

@@ -73,9 +73,13 @@ public:
         void openMemberListDialog(const QString &room_id = "");
 
 protected:
-        void closeEvent(QCloseEvent *event);
+        void closeEvent(QCloseEvent *event) override;
+        void resizeEvent(QResizeEvent *event) override;
+        void showEvent(QShowEvent *event) override;
 
 private slots:
+        //! Show or hide the sidebars based on window's size.
+        void adjustSideBars();
         //! Handle interaction with the tray icon.
         void iconActivated(QSystemTrayIcon::ActivationReason reason);
 

include/Splitter.h

@@ -29,8 +29,8 @@ public:
         void restoreSizes(int fallback);
 
 public slots:
-        void showSidebar();
         void hideSidebar();
+        void showFullRoomList();
         void showChatView();
 
 signals:

include/TopRoomBar.h

@@ -55,11 +55,14 @@ public:
         void setBorderColor(QColor &color) { borderColor_ = color; }
 
 public slots:
+        //! Add a "back-arrow" button that can switch to roomlist only view.
         void enableBackButton();
+        //! Replace the "back-arrow" button with the avatar of the room.
+        void disableBackButton();
 
 signals:
         void inviteUsers(QStringList users);
-        void showSidebar();
+        void showRoomList();
 
 protected:
         void mousePressEvent(QMouseEvent *) override

src/ChatPage.cc

@@ -65,7 +65,7 @@ ChatPage::ChatPage(QSharedPointer<UserSettings> userSettings, QWidget *parent)
         communitiesList_ = new CommunitiesList(this);
         topLayout_->addWidget(communitiesList_);
 
-        auto splitter = new Splitter(this);
+        splitter = new Splitter(this);
         splitter->setHandleWidth(0);
 
         topLayout_->addWidget(splitter);
@@ -183,8 +183,7 @@ ChatPage::ChatPage(QSharedPointer<UserSettings> userSettings, QWidget *parent)
                 emit showOverlayProgressBar();
         });
 
-        connect(splitter, &Splitter::hiddenSidebar, top_bar_, &TopRoomBar::enableBackButton);
-        connect(top_bar_, &TopRoomBar::showSidebar, splitter, &Splitter::showSidebar);
+        connect(top_bar_, &TopRoomBar::showRoomList, splitter, &Splitter::showFullRoomList);
         connect(top_bar_, &TopRoomBar::inviteUsers, this, [this](QStringList users) {
                 const auto room_id = current_room_.toStdString();
 
@@ -1314,3 +1313,35 @@ ChatPage::getProfileInfo()
           });
         // TODO http::client()->getOwnCommunities();
 }
+
+void
+ChatPage::hideSideBars()
+{
+        communitiesList_->hide();
+        sideBar_->hide();
+        top_bar_->enableBackButton();
+}
+
+void
+ChatPage::showSideBars()
+{
+        if (userSettings_->isGroupViewEnabled())
+                communitiesList_->show();
+
+        sideBar_->show();
+        top_bar_->disableBackButton();
+}
+
+int
+ChatPage::timelineWidth()
+{
+        int sidebarWidth = sideBar_->size().width();
+        sidebarWidth += communitiesList_->size().width();
+
+        return size().width() - sidebarWidth;
+}
+bool
+ChatPage::isSideBarExpanded()
+{
+        return sideBar_->size().width() > ui::sidebar::NormalSize;
+}

src/MainWindow.cc

@@ -163,6 +163,34 @@ MainWindow::MainWindow(QWidget *parent)
         }
 }
 
+void
+MainWindow::showEvent(QShowEvent *event)
+{
+        adjustSideBars();
+        QMainWindow::showEvent(event);
+}
+
+void
+MainWindow::resizeEvent(QResizeEvent *event)
+{
+        adjustSideBars();
+        QMainWindow::resizeEvent(event);
+}
+
+void
+MainWindow::adjustSideBars()
+{
+        const int timelineWidth = chat_page_->timelineWidth();
+        const int minAvailableWidth =
+          conf::sideBarCollapsePoint + ui::sidebar::CommunitiesSidebarSize;
+
+        if (timelineWidth < minAvailableWidth && !chat_page_->isSideBarExpanded()) {
+                chat_page_->hideSideBars();
+        } else {
+                chat_page_->showSideBars();
+        }
+}
+
 void
 MainWindow::restoreWindowSize()
 {

src/Splitter.cc

@@ -21,37 +21,18 @@
 #include <QSettings>
 #include <QShortcut>
 
+#include "Config.h"
 #include "Splitter.h"
 #include "Theme.h"
 
+constexpr auto MaxWidth = (1 << 24) - 1;
+
 Splitter::Splitter(QWidget *parent)
   : QSplitter(parent)
 {
         connect(this, &QSplitter::splitterMoved, this, &Splitter::onSplitterMoved);
         setChildrenCollapsible(false);
         setStyleSheet("QSplitter::handle { image: none; }");
-
-        auto showChatShortcut = new QShortcut(QKeySequence(tr("Ctrl+O", "Show chat")), parent);
-        auto showSidebarShortcut =
-          new QShortcut(QKeySequence(tr("Ctrl+L", "Show sidebar")), parent);
-
-        connect(showChatShortcut, &QShortcut::activated, this, [this]() {
-                if (count() != 2)
-                        return;
-
-                hideSidebar();
-                widget(1)->show();
-        });
-        connect(showSidebarShortcut, &QShortcut::activated, this, [this]() {
-                if (count() != 2)
-                        return;
-
-                widget(0)->setMinimumWidth(ui::sidebar::NormalSize);
-                widget(0)->setMaximumWidth(QApplication::desktop()->screenGeometry().height());
-
-                widget(0)->show();
-                widget(1)->hide();
-        });
 }
 
 void
@@ -61,7 +42,10 @@ Splitter::restoreSizes(int fallback)
         int savedWidth = settings.value("sidebar/width").toInt();
 
         auto left = widget(0);
-        if (savedWidth == ui::sidebar::SmallSize) {
+        if (savedWidth == 0) {
+                hideSidebar();
+                return;
+        } else if (savedWidth == ui::sidebar::SmallSize) {
                 if (left) {
                         left->setMinimumWidth(ui::sidebar::SmallSize);
                         left->setMaximumWidth(ui::sidebar::SmallSize);
@@ -69,21 +53,12 @@ Splitter::restoreSizes(int fallback)
                 }
         }
 
-        if (savedWidth >= ui::sidebar::NormalSize && savedWidth <= 2 * ui::sidebar::NormalSize) {
-                if (left) {
-                        left->setMinimumWidth(ui::sidebar::NormalSize);
-                        left->setMaximumWidth(2 * ui::sidebar::NormalSize);
-                        setSizes({savedWidth, fallback - savedWidth});
-                        return;
-                }
-        }
-
-        if (savedWidth == 0) {
-                hideSidebar();
-                return;
-        }
-
+        left->setMinimumWidth(ui::sidebar::NormalSize);
+        left->setMaximumWidth(2 * ui::sidebar::NormalSize);
         setSizes({ui::sidebar::NormalSize, fallback - ui::sidebar::NormalSize});
+
+        setStretchFactor(0, 0);
+        setStretchFactor(1, 1);
 }
 
 Splitter::~Splitter()
@@ -92,11 +67,7 @@ Splitter::~Splitter()
 
         if (left) {
                 QSettings settings;
-
-                if (!left->isVisible())
-                        settings.setValue("sidebar/width", 0);
-                else
-                        settings.setValue("sidebar/width", left->width());
+                settings.setValue("sidebar/width", left->width());
         }
 }
 
@@ -143,49 +114,55 @@ Splitter::onSplitterMoved(int pos, int index)
 
                         // if we are coming from the left, the cursor should
                         // end up on the second widget.
-                        if (extended.contains(pos)) {
+                        if (extended.contains(pos) &&
+                            right->size().width() >=
+                              conf::sideBarCollapsePoint + ui::sidebar::NormalSize) {
                                 left->setMinimumWidth(ui::sidebar::NormalSize);
                                 left->setMaximumWidth(2 * ui::sidebar::NormalSize);
 
                                 leftMoveCount_ = 0;
-                        } else if (left->rect().contains(left->mapFromGlobal(QCursor::pos()))) {
-                                hideSidebar();
                         }
                 }
         }
 }
-void
-Splitter::showChatView()
-{
-        if (count() != 2)
-                return;
-
-        auto right = widget(1);
-
-        // We are in Roomlist-only view so we'll switch into Chat-only view.
-        if (!right->isVisible()) {
-                right->show();
-                hideSidebar();
-        }
-}
-
-void
-Splitter::showSidebar()
-{
-        auto left = widget(0);
-        if (left) {
-                left->setMinimumWidth(ui::sidebar::SmallSize);
-                left->setMaximumWidth(ui::sidebar::SmallSize);
-                left->show();
-        }
-}
 
 void
 Splitter::hideSidebar()
 {
         auto left = widget(0);
-        if (left) {
+        if (left)
                 left->hide();
-                emit hiddenSidebar();
+}
+
+void
+Splitter::showChatView()
+{
+        auto left  = widget(0);
+        auto right = widget(1);
+
+        if (right->isHidden()) {
+                left->hide();
+                right->show();
+
+                // Restore previous size.
+                if (left->minimumWidth() == ui::sidebar::SmallSize) {
+                        left->setMinimumWidth(ui::sidebar::SmallSize);
+                        left->setMaximumWidth(ui::sidebar::SmallSize);
+                } else {
+                        left->setMinimumWidth(ui::sidebar::NormalSize);
+                        left->setMaximumWidth(2 * ui::sidebar::NormalSize);
+                }
         }
 }
+
+void
+Splitter::showFullRoomList()
+{
+        auto left  = widget(0);
+        auto right = widget(1);
+
+        right->hide();
+
+        left->show();
+        left->setMaximumWidth(MaxWidth);
+}

src/TopRoomBar.cc

@@ -83,11 +83,7 @@ TopRoomBar::TopRoomBar(QWidget *parent)
         backBtn_->setIconSize(QSize(buttonSize_ / 2, buttonSize_ / 2));
         backBtn_->hide();
 
-        connect(backBtn_, &QPushButton::clicked, this, [this]() {
-                backBtn_->hide();
-                avatar_->show();
-                emit showSidebar();
-        });
+        connect(backBtn_, &QPushButton::clicked, this, &TopRoomBar::showRoomList);
 
         topLayout_->addWidget(avatar_);
         topLayout_->addWidget(backBtn_);
@@ -136,6 +132,13 @@ TopRoomBar::enableBackButton()
         backBtn_->show();
 }
 
+void
+TopRoomBar::disableBackButton()
+{
+        avatar_->show();
+        backBtn_->hide();
+}
+
 void
 TopRoomBar::updateRoomAvatarFromName(const QString &name)
 {