Qt: Automatically scroll the packet list.

Add an "Auto Scroll in Live Capture" action to the Go menu. It's in the
View menu in the GTK+ UI but it seems to make more sense as a navigation
item.

Use a timeout interval for automatic scrolling. I haven't run any tests
to see if this makes a difference but it would seem that the less
drawing we do during a high speed capture the better, particularly for
remote displays.

Update the x-stay-last icons.

Note that we might want to make prefs.capture_auto_scroll a "recent"
setting.

Mark auto_scroll_live and packet_list_check_end GTK+ only.

Bug: 10601
Co-authored-by: Gerald Combs <gerald@wireshark.org>
Change-Id: I645d27c0814f0e4a0d5b01ae68be366847e2522d
Reviewed-on: https://code.wireshark.org/review/7292
Reviewed-by: Gerald Combs <gerald@wireshark.org>

9 files changed, 112 insertions, 20 deletions

diff --git a/ui/preference_utils.h b/ui/preference_utils.h
index 074b974844..e4117d682e 100644
--- a/ui/preference_utils.h
+++ b/ui/preference_utils.h
@@ -70,7 +70,7 @@ extern void reset_stashed_pref(pref_t *pref);
 
 /** If autoscroll in live captures is active or not
  */
-extern gboolean auto_scroll_live;
+extern gboolean auto_scroll_live; /* GTK+ only. */
 
 /** Fill in capture options with values from the preferences
  */
diff --git a/ui/qt/capture_file.cpp b/ui/qt/capture_file.cpp
index a32f225f15..a15e8ebdba 100644
--- a/ui/qt/capture_file.cpp
+++ b/ui/qt/capture_file.cpp
@@ -40,6 +40,7 @@ capture_file cfile;
 // To do:
 // - Add getters and (if needed) setters:
 //   - Full filename
+//   - Capture state (stopped, prepared, running).
 
 QString CaptureFile::no_capture_file_ = QObject::tr("[no capture file]");
 
diff --git a/ui/qt/main_window.cpp b/ui/qt/main_window.cpp
index c69d50a68d..7eb7b702b7 100644
--- a/ui/qt/main_window.cpp
+++ b/ui/qt/main_window.cpp
@@ -187,7 +187,6 @@ MainWindow::MainWindow(QWidget *parent) :
     setForCapturedPackets(false);
     setMenusForSelectedPacket();
     setMenusForSelectedTreeRow();
-    setForCaptureInProgress(false);
     setMenusForFileSet(false);
     interfaceSelectionChanged();
     loadWindowGeometry();
@@ -202,7 +201,7 @@ MainWindow::MainWindow(QWidget *parent) :
     connect(wsApp, SIGNAL(profileChanging()), this, SLOT(saveWindowGeometry()));
     connect(wsApp, SIGNAL(preferencesChanged()), this, SLOT(layoutPanes()));
     connect(wsApp, SIGNAL(preferencesChanged()), this, SLOT(layoutToolbars()));
-    connect(wsApp, SIGNAL(preferencesChanged()), this, SLOT(updateNameResolutionActions()));
+    connect(wsApp, SIGNAL(preferencesChanged()), this, SLOT(updatePreferenceActions()));
     connect(wsApp, SIGNAL(preferencesChanged()), this, SLOT(zoomText()));
 
     connect(wsApp, SIGNAL(updateRecentItemStatus(const QString &, qint64, bool)), this, SLOT(updateRecentFiles()));
@@ -286,7 +285,8 @@ MainWindow::MainWindow(QWidget *parent) :
     initShowHideMainWidgets();
     initTimeDisplayFormatMenu();
     initTimePrecisionFormatMenu();
-    updateNameResolutionActions();
+    updatePreferenceActions();
+    setForCaptureInProgress(false);
 
     connect(&capture_file_, SIGNAL(captureCapturePrepared(capture_session *)),
             this, SLOT(captureCapturePrepared(capture_session *)));
@@ -388,6 +388,8 @@ MainWindow::MainWindow(QWidget *parent) :
             packet_list_, SLOT(redrawVisiblePackets()));
     connect(packet_list_, SIGNAL(doubleClicked(QModelIndex)),
             this, SLOT(openPacketDialog()));
+    connect(packet_list_, SIGNAL(packetListScrolled(bool)),
+            main_ui_->actionGoAutoScroll, SLOT(setChecked(bool)));
 
     connect(proto_tree_, SIGNAL(protoItemSelected(QString&)),
             main_ui_->statusBar, SLOT(pushFieldStatus(QString&)));
@@ -1420,6 +1422,7 @@ void MainWindow::initMainToolbarIcons()
     main_ui_->actionGoGoToPacket->setIcon(StockIcon("go-jump"));
     main_ui_->actionGoFirstPacket->setIcon(StockIcon("go-first"));
     main_ui_->actionGoLastPacket->setIcon(StockIcon("go-last"));
+    main_ui_->actionGoAutoScroll->setIcon(StockIcon("x-stay-last"));
 
     main_ui_->actionViewColorizePacketList->setIcon(StockIcon("x-colorize-packets"));
     main_ui_->actionViewColorizePacketList->setChecked(recent.packet_list_colorize);
@@ -1818,11 +1821,12 @@ void MainWindow::setForCaptureInProgress(gboolean capture_in_progress)
 {
     setMenusForCaptureInProgress(capture_in_progress);
 
-//#ifdef HAVE_LIBPCAP
+#ifdef HAVE_LIBPCAP
+    packet_list_->setCaptureInProgress(capture_in_progress);
 //    set_toolbar_for_capture_in_progress(capture_in_progress);
 
 //    set_capture_if_dialog_for_capture_in_progress(capture_in_progress);
-//#endif
+#endif
 }
 
 /*
diff --git a/ui/qt/main_window.h b/ui/qt/main_window.h
index 5310c00033..05f73e3f61 100644
--- a/ui/qt/main_window.h
+++ b/ui/qt/main_window.h
@@ -190,7 +190,7 @@ public slots:
     void layoutPanes();
     void applyRecentPaneGeometry();
     void layoutToolbars();
-    void updateNameResolutionActions();
+    void updatePreferenceActions();
 
     void captureCapturePrepared(capture_session *);
     void captureCaptureUpdateStarted(capture_session *);
@@ -324,6 +324,7 @@ private slots:
     void on_actionViewReload_triggered();
 
     void on_actionGoGoToPacket_triggered();
+    void on_actionGoAutoScroll_toggled(bool checked);
     void resetPreviousFocus();
 
 #ifdef HAVE_LIBPCAP
diff --git a/ui/qt/main_window.ui b/ui/qt/main_window.ui
index 29a9efba84..6a9901a3a4 100644
--- a/ui/qt/main_window.ui
+++ b/ui/qt/main_window.ui
@@ -225,6 +225,8 @@
     <addaction name="actionGoPreviousPacket"/>
     <addaction name="actionGoFirstPacket"/>
     <addaction name="actionGoLastPacket"/>
+    <addaction name="separator"/>
+    <addaction name="actionGoAutoScroll"/>
    </widget>
    <widget class="QMenu" name="menuView">
     <property name="title">
@@ -568,6 +570,7 @@
    <addaction name="actionGoGoToPacket"/>
    <addaction name="actionGoFirstPacket"/>
    <addaction name="actionGoLastPacket"/>
+   <addaction name="actionGoAutoScroll"/>
    <addaction name="separator"/>
    <addaction name="actionViewColorizePacketList"/>
    <addaction name="separator"/>
@@ -2293,6 +2296,17 @@
     <string>Show the linked packet in a separate window.</string>
    </property>
   </action>
+  <action name="actionGoAutoScroll">
+   <property name="checkable">
+    <bool>true</bool>
+   </property>
+   <property name="text">
+    <string>Auto Scroll in Li&amp;ve Capture</string>
+   </property>
+   <property name="toolTip">
+    <string>Automatically scroll to the last packet during a live capture.</string>
+   </property>
+  </action>
  </widget>
  <layoutdefault spacing="6" margin="11"/>
  <customwidgets>
diff --git a/ui/qt/main_window_slots.cpp b/ui/qt/main_window_slots.cpp
index 8291e0d3c8..bd366ae0e8 100644
--- a/ui/qt/main_window_slots.cpp
+++ b/ui/qt/main_window_slots.cpp
@@ -415,11 +415,14 @@ void MainWindow::layoutToolbars()
     main_ui_->mainToolBar->setToolButtonStyle(tbstyle);
 }
 
-void MainWindow::updateNameResolutionActions()
+void MainWindow::updatePreferenceActions()
 {
     main_ui_->actionViewNameResolutionPhysical->setChecked(gbl_resolv_flags.mac_name);
     main_ui_->actionViewNameResolutionNetwork->setChecked(gbl_resolv_flags.network_name);
     main_ui_->actionViewNameResolutionTransport->setChecked(gbl_resolv_flags.transport_name);
+
+    // Should this be a "recent" setting?
+    main_ui_->actionGoAutoScroll->setChecked(prefs.capture_auto_scroll);
 }
 
 void MainWindow::filterAction(QString &action_filter, FilterAction::Action action, FilterAction::ActionType type)
@@ -2693,6 +2696,11 @@ void MainWindow::on_actionGoGoToPacket_triggered() {
     main_ui_->goToLineEdit->setFocus();
 }
 
+void MainWindow::on_actionGoAutoScroll_toggled(bool checked)
+{
+    packet_list_->setAutoScroll(checked);
+}
+
 void MainWindow::resetPreviousFocus() {
     previous_focus_ = NULL;
 }
diff --git a/ui/qt/packet_list.cpp b/ui/qt/packet_list.cpp
index 428a51f1f7..4d6e3905ac 100644
--- a/ui/qt/packet_list.cpp
+++ b/ui/qt/packet_list.cpp
@@ -60,11 +60,12 @@
 #include <QScrollBar>
 #include <QTabWidget>
 #include <QTextEdit>
+#include <QTimerEvent>
 #include <QTreeWidget>
 
 // To do:
-// - Heading context menus
 // - Catch column reordering and rebuild the column list accoringly.
+// - Use a timer to trigger automatic scrolling.
 
 // If we ever add the ability to open multiple capture files we might be
 // able to use something like QMap<capture_file *, PacketList *> to match
@@ -72,6 +73,7 @@
 static PacketList *gbl_cur_packet_list = NULL;
 
 const int max_comments_to_fetch_ = 20000000; // Arbitrary
+const int tail_update_interval_ = 100; // Milliseconds.
 
 guint
 packet_list_append(column_info *cinfo, frame_data *fdata)
@@ -135,13 +137,7 @@ packet_list_select_row_from_data(frame_data *fdata_needle)
 gboolean
 packet_list_check_end(void)
 {
-    if (gbl_cur_packet_list) {
-        QScrollBar *sb = gbl_cur_packet_list->verticalScrollBar();
-        if (sb && sb->isVisible() && sb->value() == sb->maximum()) {
-            return TRUE;
-        }
-    }
-    return FALSE;
+    return FALSE; // GTK+ only.
 }
 
 void
@@ -230,7 +226,9 @@ PacketList::PacketList(QWidget *parent) :
     byte_view_tab_(NULL),
     cap_file_(NULL),
     decode_as_(NULL),
-    ctx_column_(-1)
+    ctx_column_(-1),
+    capture_in_progress_(false),
+    tail_timer_id_(0)
 {
     QMenu *submenu, *subsubmenu;
     QAction *action;
@@ -419,6 +417,8 @@ PacketList::PacketList(QWidget *parent) :
     connect(header(), SIGNAL(customContextMenuRequested(QPoint)),
                 SLOT(showHeaderMenu(QPoint)));
     connect(header(), SIGNAL(sectionResized(int,int,int)), this, SLOT(sectionResized(int,int,int)));
+
+    connect(verticalScrollBar(), SIGNAL(actionTriggered(int)), this, SLOT(vScrollBarActionTriggered(int)));
 }
 
 void PacketList::setProtoTree (ProtoTree *proto_tree) {
@@ -519,6 +519,27 @@ void PacketList::contextMenuEvent(QContextMenuEvent *event)
     decode_as_->setData(QVariant());
 }
 
+// Auto scroll if:
+// - We're not at the end
+// - We are capturing
+// - actionGoAutoScroll in the main UI is checked.
+// - It's been more than tail_update_interval_ ms since we last scrolled
+// - The last user-set vertical scrollbar position was at the end.
+
+// Using a timer assumes that we can save CPU overhead by updating
+// periodically. If that's not the case we can dispense with it and call
+// scrollToBottom() from rowsInserted().
+void PacketList::timerEvent(QTimerEvent *event)
+{
+    if (rows_inserted_
+            && event->timerId() == tail_timer_id_
+            && capture_in_progress_
+            && tail_at_end_) {
+        scrollToBottom();
+        rows_inserted_ = false;
+    }
+}
+
 void PacketList::markFramesReady()
 {
     packets_bar_update();
@@ -661,6 +682,18 @@ void PacketList::recolorPackets()
     redrawVisiblePackets();
 }
 
+void PacketList::setAutoScroll(bool enabled)
+{
+    tail_at_end_ = enabled;
+    if (enabled) {
+        scrollToBottom();
+        if (tail_timer_id_ < 1) tail_timer_id_ = startTimer(tail_update_interval_);
+    } else if (tail_timer_id_ > 0) {
+        killTimer(tail_timer_id_);
+        tail_timer_id_ = 0;
+    }
+}
+
 void PacketList::freeze()
 {
     setUpdatesEnabled(false);
@@ -1129,6 +1162,25 @@ void PacketList::sectionResized(int, int, int)
     }
 }
 
+// We need to tell when the user has scrolled the packet list, either to
+// the end or anywhere other than the end.
+void PacketList::vScrollBarActionTriggered(int)
+{
+    // If we're scrolling with a mouse wheel or trackpad sliderPosition can end up
+    // past the end.
+    tail_at_end_ = (verticalScrollBar()->sliderPosition() >= verticalScrollBar()->maximum());
+
+    if (capture_in_progress_ && prefs.capture_auto_scroll) {
+        emit packetListScrolled(tail_at_end_);
+    }
+}
+
+void PacketList::rowsInserted(const QModelIndex &parent, int start, int end)
+{
+    QTreeView::rowsInserted(parent, start, end);
+    rows_inserted_ = true;
+}
+
 /*
  * Editor modelines
  *
diff --git a/ui/qt/packet_list.h b/ui/qt/packet_list.h
index 04fcf74e2e..357533c67b 100644
--- a/ui/qt/packet_list.h
+++ b/ui/qt/packet_list.h
@@ -28,10 +28,12 @@
 #include "proto_tree.h"
 #include "related_packet_delegate.h"
 
-#include <QTreeView>
 #include <QMenu>
+#include <QTime>
+#include <QTreeView>
 
 class QAction;
+class QTimerEvent;
 
 class PacketList : public QTreeView
 {
@@ -63,12 +65,17 @@ public:
     void setPacketComment(QString new_comment);
     QString allPacketComments();
     void recolorPackets();
+    void setAutoScroll(bool enabled = true);
+    void setCaptureInProgress(bool in_progress = false) { capture_in_progress_ = in_progress; tail_at_end_ = in_progress; }
 
 protected:
     void showEvent (QShowEvent *);
     void selectionChanged (const QItemSelection & selected, const QItemSelection & deselected);
     void contextMenuEvent(QContextMenuEvent *event);
+    void timerEvent(QTimerEvent *event);
 
+protected slots:
+    void rowsInserted(const QModelIndex &parent, int start, int end);
 
 private:
     PacketListModel *packet_list_model_;
@@ -87,6 +94,10 @@ private:
     int header_ctx_column_;
     QAction *show_hide_separator_;
     QList<QAction *>show_hide_actions_;
+    bool capture_in_progress_;
+    int tail_timer_id_;
+    bool tail_at_end_;
+    bool rows_inserted_;
 
     void markFramesReady();
     void setFrameMark(gboolean set, frame_data *fdata);
@@ -94,12 +105,12 @@ private:
     void setFrameReftime(gboolean set, frame_data *fdata);
     void setColumnVisibility();
     void initHeaderContextMenu();
-
 signals:
     void packetDissectionChanged();
     void packetSelectionChanged();
     void showPreferences(PreferencesDialog::PreferencesPane start_pane);
     void editColumn(int column);
+    void packetListScrolled(bool at_end);
 
 public slots:
     void setCaptureFile(capture_file *cf);
@@ -124,6 +135,7 @@ private slots:
     void headerMenuTriggered();
     void columnVisibilityTriggered();
     void sectionResized(int, int, int);
+    void vScrollBarActionTriggered(int);
 };
 
 #endif // PACKET_LIST_H
diff --git a/ui/ui_util.h b/ui/ui_util.h
index 7ebd59bd3d..b76e218951 100644
--- a/ui/ui_util.h
+++ b/ui/ui_util.h
@@ -74,7 +74,7 @@ void packet_list_queue_draw(void);
 void packet_list_select_first_row(void);
 void packet_list_select_last_row(void);
 void packet_list_moveto_end(void);
-gboolean packet_list_check_end(void);
+gboolean packet_list_check_end(void); /* GTK+ only */
 gboolean packet_list_select_row_from_data(frame_data *fdata_needle);
 void packet_list_resize_column(gint col);