Fix #121 by implementing sticky scrolling

diff --git a/pv/mainwindow.cpp b/pv/mainwindow.cpp
index 3a775edde104d2500f00397730e63c8844de74d3..6d28194bb87cbed491e00a3aa2bc21436e8976b3 100644 (file)
--- a/pv/mainwindow.cpp
+++ b/pv/mainwindow.cpp
@@ -106,6 +106,7 @@ MainWindow::MainWindow(DeviceManager &device_manager,
        action_view_zoom_out_(new QAction(this)),
        action_view_zoom_fit_(new QAction(this)),
        action_view_zoom_one_to_one_(new QAction(this)),
+       action_view_sticky_scrolling_(new QAction(this)),
        action_view_show_cursors_(new QAction(this)),
        action_about_(new QAction(this))
 #ifdef ENABLE_DECODE
@@ -160,6 +161,11 @@ QAction* MainWindow::action_view_zoom_one_to_one() const
        return action_view_zoom_one_to_one_;
 }
 
+QAction* MainWindow::action_view_sticky_scrolling() const
+{
+       return action_view_sticky_scrolling_;
+}
+
 QAction* MainWindow::action_view_show_cursors() const
 {
        return action_view_show_cursors_;
@@ -411,6 +417,18 @@ void MainWindow::setup_ui()
                QString::fromUtf8("actionViewZoomOneToOne"));
        menu_view->addAction(action_view_zoom_one_to_one_);
 
+       menu_file->addSeparator();
+
+       action_view_sticky_scrolling_->setCheckable(true);
+       action_view_sticky_scrolling_->setChecked(true);
+       action_view_sticky_scrolling_->setShortcut(QKeySequence(Qt::Key_R));
+       action_view_sticky_scrolling_->setObjectName(
+               QString::fromUtf8("actionViewStickyScrolling"));
+       action_view_sticky_scrolling_->setText(tr("Sticky Sc&rolling"));
+       menu_view->addAction(action_view_sticky_scrolling_);
+
+       view_->enable_sticky_scrolling(action_view_sticky_scrolling_->isChecked());
+
        menu_view->addSeparator();
 
        action_view_show_cursors_->setCheckable(true);
@@ -473,6 +491,11 @@ void MainWindow::setup_ui()
                SLOT(capture_state_changed(int)));
        connect(&session_, SIGNAL(device_selected()), this,
                SLOT(device_selected()));
+
+       // Setup view_ events
+       connect(view_, SIGNAL(sticky_scrolling_changed(bool)), this,
+               SLOT(sticky_scrolling_changed(bool)));
+
 }
 
 void MainWindow::select_init_device() {
@@ -715,6 +738,11 @@ void MainWindow::on_actionViewZoomOneToOne_triggered()
        view_->zoom_one_to_one();
 }
 
+void MainWindow::on_actionViewStickyScrolling_triggered()
+{
+       view_->enable_sticky_scrolling(action_view_sticky_scrolling_->isChecked());
+}
+
 void MainWindow::on_actionViewShowCursors_triggered()
 {
        assert(view_);
@@ -732,6 +760,11 @@ void MainWindow::on_actionAbout_triggered()
        dlg.exec();
 }
 
+void MainWindow::sticky_scrolling_changed(bool state)
+{
+       action_view_sticky_scrolling_->setChecked(state);
+}
+
 void MainWindow::add_decoder(srd_decoder *decoder)
 {
 #ifdef ENABLE_DECODE

diff --git a/pv/mainwindow.hpp b/pv/mainwindow.hpp
index 6a4bdfc80f4b46134fde599d33f4eea2dda469a1..ad7e6b2bdb6f48a0d2723335eb9cc598a682675e 100644 (file)
--- a/pv/mainwindow.hpp
+++ b/pv/mainwindow.hpp
@@ -90,6 +90,7 @@ public:
        QAction* action_view_zoom_out() const;
        QAction* action_view_zoom_fit() const;
        QAction* action_view_zoom_one_to_one() const;
+       QAction* action_view_sticky_scrolling() const;
        QAction* action_view_show_cursors() const;
        QAction* action_about() const;
 
@@ -152,6 +153,8 @@ private Q_SLOTS:
 
        void on_actionViewZoomOneToOne_triggered();
 
+       void on_actionViewStickyScrolling_triggered();
+
        void on_actionViewShowCursors_triggered();
 
        void on_actionAbout_triggered();
@@ -161,6 +164,8 @@ private Q_SLOTS:
        void capture_state_changed(int state);
        void device_selected();
 
+       void sticky_scrolling_changed(bool state);
+
 private:
        DeviceManager &device_manager_;
 
@@ -181,6 +186,7 @@ private:
        QAction *const action_view_zoom_out_;
        QAction *const action_view_zoom_fit_;
        QAction *const action_view_zoom_one_to_one_;
+       QAction *const action_view_sticky_scrolling_;
        QAction *const action_view_show_cursors_;
        QAction *const action_about_;
 

diff --git a/pv/toolbars/mainbar.cpp b/pv/toolbars/mainbar.cpp
index b404b3da45b32666f335fbee88d773c657b0b855..a1761291ddb835a4ba84c1bcc176849d676e821e 100644 (file)
--- a/pv/toolbars/mainbar.cpp
+++ b/pv/toolbars/mainbar.cpp
@@ -135,13 +135,19 @@ MainBar::MainBar(Session &session, MainWindow &main_window) :
        add_decoder_button->setMenu(main_window_.menu_decoder_add());
 #endif
 
-       // Setup the menu
+       // Setup the burger menu
        QMenu *const menu = new QMenu(this);
 
+       QMenu *const menu_view = new QMenu;
+       menu_view->setTitle(tr("&View"));
+       menu_view->addAction(main_window.action_view_sticky_scrolling());
+
        QMenu *const menu_help = new QMenu;
        menu_help->setTitle(tr("&Help"));
        menu_help->addAction(main_window.action_about());
 
+       menu->addAction(menu_view->menuAction());
+       menu->addSeparator();
        menu->addAction(menu_help->menuAction());
        menu->addSeparator();
        menu->addAction(main_window.action_quit());

diff --git a/pv/view/view.cpp b/pv/view/view.cpp
index 2ae0a7144cba4b9b15abbc34f3e9265e14f43250..130d2d788cfaf862cbb2c83b03fbac8e48f7e4a0 100644 (file)
--- a/pv/view/view.cpp
+++ b/pv/view/view.cpp
@@ -86,6 +86,7 @@ const double View::MaxScale = 1e9;
 const double View::MinScale = 1e-15;
 
 const int View::MaxScrollValue = INT_MAX / 2;
+const int View::MaxViewAutoUpdateRate = 25; // No more than 25 Hz
 
 const int View::ScaleUnits[3] = {1, 2, 5};
 
@@ -98,6 +99,7 @@ View::View(Session &session, QWidget *parent) :
        scale_(1e-3),
        offset_(0),
        updating_scroll_(false),
+       sticky_scrolling_(false), // Default setting is set in MainWindow::setup_ui()
        tick_period_(0.0),
        tick_prefix_(0),
        show_cursors_(false),
@@ -136,6 +138,11 @@ View::View(Session &session, QWidget *parent) :
                this, SLOT(process_sticky_events()));
        lazy_event_handler_.setSingleShot(true);
 
+       connect(&delayed_view_updater_, SIGNAL(timeout()),
+               this, SLOT(perform_delayed_view_update()));
+       delayed_view_updater_.setSingleShot(true);
+       delayed_view_updater_.setInterval(1000 / MaxViewAutoUpdateRate);
+
        setViewport(viewport_);
 
        viewport_->installEventFilter(this);
@@ -288,6 +295,13 @@ void View::zoom_one_to_one()
 
 void View::set_scale_offset(double scale, double offset)
 {
+       // Disable sticky scrolling when acquisition runs and user drags the viewport
+       if ((scale_ == scale) && (offset_ != offset) &&
+                       sticky_scrolling_ && (session_.get_capture_state() == Session::Running)) {
+               sticky_scrolling_ = false;
+               sticky_scrolling_changed(false);
+       }
+
        scale_ = scale;
        offset_ = offset;
 
@@ -339,6 +353,11 @@ pair<double, double> View::get_time_extents() const
        return make_pair(left_time, right_time);
 }
 
+void View::enable_sticky_scrolling(bool state)
+{
+       sticky_scrolling_ = state;
+}
+
 bool View::cursors_shown() const
 {
        return show_cursors_;
@@ -674,6 +693,13 @@ void View::h_scroll_value_changed(int value)
        if (updating_scroll_)
                return;
 
+       // Disable sticky scrolling when user moves the horizontal scroll bar
+       // during a running acquisition
+       if (sticky_scrolling_ && (session_.get_capture_state() == Session::Running)) {
+               sticky_scrolling_ = false;
+               sticky_scrolling_changed(false);
+       }
+
        const int range = horizontalScrollBar()->maximum();
        if (range < MaxScrollValue)
                offset_ = scale_ * value;
@@ -821,10 +847,31 @@ void View::signals_changed()
 
 void View::data_updated()
 {
-       // Update the scroll bars
-       update_scroll();
+       if (sticky_scrolling_) {
+               if (!delayed_view_updater_.isActive())
+                       delayed_view_updater_.start();
+       } else {
+               update_scroll();
+               ruler_->update();
+               viewport_->update();
+       }
+}
+
+void View::perform_delayed_view_update()
+{
+       if (sticky_scrolling_) {
+               // Make right side of the view sticky
+               double length = 0, offset;
+               get_scroll_layout(length, offset);
+
+               const QSize areaSize = viewport_->size();
+               length = max(length - areaSize.width(), 0.0);
+
+               offset_ = scale_ * length;
+       }
 
-       // Repaint the view
+       update_scroll();
+       ruler_->update();
        viewport_->update();
 }
 

diff --git a/pv/view/view.hpp b/pv/view/view.hpp
index 3e0a347142fb91b69b72301c4adeaa60e109e07b..b29fb157dce383eec55535fcd187ecf104eaa9b7 100644 (file)
--- a/pv/view/view.hpp
+++ b/pv/view/view.hpp
@@ -69,6 +69,7 @@ private:
        static const double MinScale;
 
        static const int MaxScrollValue;
+       static const int MaxViewAutoUpdateRate;
 
        static const int ScaleUnits[3];
 
@@ -152,6 +153,12 @@ public:
 
        std::pair<double, double> get_time_extents() const;
 
+       /**
+        * Enables or disables sticky scrolling, i.e. the view always shows
+        * the most recent samples when capturing data.
+        */
+       void enable_sticky_scrolling(bool state);
+
        /**
         * Returns true if cursors are displayed. false otherwise.
         */
@@ -200,6 +207,8 @@ Q_SIGNALS:
 
        void scale_offset_changed();
 
+       void sticky_scrolling_changed(bool state);
+
 private:
        void get_scroll_layout(double &length, double &offset) const;
 
@@ -269,6 +278,8 @@ private Q_SLOTS:
        void signals_changed();
        void data_updated();
 
+       void perform_delayed_view_update();
+
        void process_sticky_events();
 
        void on_hover_point_changed();
@@ -287,6 +298,8 @@ private:
        double offset_;
 
        bool updating_scroll_;
+       bool sticky_scrolling_;
+       QTimer delayed_view_updater_;
 
        double tick_period_;
        unsigned int tick_prefix_;