Merge pull request #1245 from dogmaphobic/messageHandler

Message Handler

qgroundcontrol.pro

@@ -329,7 +329,7 @@ FORMS += \
     src/ui/uas/UASQuickViewItemSelect.ui \
     src/ui/QGCTabbedInfoView.ui \
     src/ui/UASRawStatusView.ui \
-    src/ui/uas/QGCMessageView.ui \
+    src/ui/uas/UASMessageView.ui \
     src/ui/JoystickButton.ui \
     src/ui/JoystickAxis.ui \
     src/ui/configuration/terminalconsole.ui \
@@ -458,7 +458,7 @@ HEADERS += \
     src/ui/QGCTabbedInfoView.h \
     src/ui/UASRawStatusView.h \
     src/ui/PrimaryFlightDisplay.h \
-    src/ui/uas/QGCMessageView.h \
+    src/ui/uas/UASMessageView.h \
     src/ui/JoystickButton.h \
     src/ui/JoystickAxis.h \
     src/ui/configuration/console.h \
@@ -494,7 +494,8 @@ HEADERS += \
     src/ui/QGCLinkConfiguration.h \
     src/comm/LinkConfiguration.h \
     src/ui/QGCCommConfiguration.h \
-    src/ui/QGCUDPLinkConfiguration.h
+    src/ui/QGCUDPLinkConfiguration.h \
+    src/uas/UASMessageHandler.h
 
 SOURCES += \
     src/main.cc \
@@ -604,7 +605,7 @@ SOURCES += \
     src/ui/PrimaryFlightDisplay.cc \
     src/ui/JoystickButton.cc \
     src/ui/JoystickAxis.cc \
-    src/ui/uas/QGCMessageView.cc \
+    src/ui/uas/UASMessageView.cc \
     src/ui/configuration/terminalconsole.cpp \
     src/ui/configuration/console.cpp \
     src/ui/configuration/SerialSettingsDialog.cc \
@@ -635,7 +636,8 @@ SOURCES += \
     src/ui/QGCLinkConfiguration.cc \
     src/comm/LinkConfiguration.cc \
     src/ui/QGCCommConfiguration.cc \
-    src/ui/QGCUDPLinkConfiguration.cc
+    src/ui/QGCUDPLinkConfiguration.cc \
+    src/uas/UASMessageHandler.cc
 
 #
 # Unit Test specific configuration goes here

src/QGCApplication.cc

@@ -54,6 +54,7 @@
 #include "QGCSingleton.h"
 #include "LinkManager.h"
 #include "UASManager.h"
+#include "UASMessageHandler.h"
 #include "AutoPilotPluginManager.h"
 #include "QGCTemporaryFile.h"
 #include "QGCFileDialog.h"
@@ -426,6 +427,11 @@ void QGCApplication::_createSingletons(void)
     Q_UNUSED(pluginManager);
     Q_ASSERT(pluginManager);
 
+    // Need UASManager
+    UASMessageHandler* messageHandler = UASMessageHandler::_createSingleton();
+    Q_UNUSED(messageHandler);
+    Q_ASSERT(messageHandler);
+
     // Needs UASManager
     FactSystem* factSystem = FactSystem::_createSingleton();
     Q_UNUSED(factSystem);
@@ -460,6 +466,7 @@ void QGCApplication::_destroySingletons(void)
 
     MAVLinkProtocol::_deleteSingleton();
     FactSystem::_deleteSingleton();
+    UASMessageHandler::_deleteSingleton();
     AutoPilotPluginManager::_deleteSingleton();
     UASManager::_deleteSingleton();
     LinkManager::_deleteSingleton();

src/ui/uas/QGCMessageView.cc → src/uas/UASMessageHandler.cc

-#include <QMenu>
-#include <QScrollBar>
+/*=====================================================================
 
-#include "QGCMessageView.h"
-#include "GAudioOutput.h"
-#include "QGCUnconnectedInfoWidget.h"
+QGroundControl Open Source Ground Control Station
+
+(c) 2009 - 2011 QGROUNDCONTROL PROJECT <http://www.qgroundcontrol.org>
+
+This file is part of the QGROUNDCONTROL project
+
+    QGROUNDCONTROL is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    QGROUNDCONTROL is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with QGROUNDCONTROL. If not, see <http://www.gnu.org/licenses/>.
+
+======================================================================*/
+
+/*!
+ * @file
+ *   @brief Message Handler
+ *   @author Gus Grubba <mavlink@grubba.com>
+ */
+
+#include "QGCApplication.h"
+#include "UASMessageHandler.h"
 #include "UASManager.h"
-#include "ui_QGCMessageView.h"
 
-QGCMessageView::QGCMessageView(QWidget *parent) :
-    QWidget(parent),
-    activeUAS(NULL),
-    ui(new Ui::QGCMessageView)
+UASMessage::UASMessage(int componentid, int severity, QString text)
+{
+    _compId   = componentid;
+    _severity = severity;
+    _text     = text;
+}
+
+IMPLEMENT_QGC_SINGLETON(UASMessageHandler, UASMessageHandler)
+
+UASMessageHandler::UASMessageHandler(QObject *parent)
+    : QGCSingleton(parent)
+    , _activeUAS(NULL)
 {
-    setObjectName("QUICKVIEW_MESSAGE_CONSOLE")  ;
-
-    ui->setupUi(this);
-    setStyleSheet("QPlainTextEdit { border: 0px }");
-
-    // Construct initial widget
-    connectWidget = new QGCUnconnectedInfoWidget(this);
-    ui->horizontalLayout->addWidget(connectWidget);
-    ui->plainTextEdit->hide();
-
-    // Enable the right-click menu for the text editor. This works because the plainTextEdit
-    // widget has its context menu policy set to its actions list. So any actions we add
-    // to this widget's action list will be automatically displayed.
-    // We only have the clear action right now.
-    QAction* clearAction = new QAction(tr("Clear Text"), this);
-    connect(clearAction, SIGNAL(triggered()), ui->plainTextEdit, SLOT(clear()));
-    ui->plainTextEdit->addAction(clearAction);
-
-    // Connect to the currently active UAS.
-    setActiveUAS(UASManager::instance()->getActiveUAS());
     connect(UASManager::instance(), SIGNAL(activeUASSet(UASInterface*)), this, SLOT(setActiveUAS(UASInterface*)));
+    emit textMessageReceived(NULL);
 }
 
-QGCMessageView::~QGCMessageView()
+UASMessageHandler::~UASMessageHandler()
 {
-    // The only thing we need to delete is the ui because it's the only thing not cleaned up automatically
-    // by the deletion of its parent.
-    delete ui;
+    clearMessages();
 }
 
-void QGCMessageView::setActiveUAS(UASInterface* uas)
+void UASMessageHandler::clearMessages()
 {
-    // If we were already attached to an autopilot, disconnect it, restoring
-    // the widget to its initial state as needed.
-    if (activeUAS)
-    {
-        disconnect(activeUAS, SIGNAL(textMessageReceived(int,int,int,QString)), this, SLOT(handleTextMessage(int,int,int,QString)));
-        ui->plainTextEdit->clear();
-        activeUAS = NULL;
+    _mutex.lock();
+    while(_messages.count()) {
+        delete _messages.last();
+        _messages.pop_back();
     }
+    _mutex.unlock();
+}
 
+void UASMessageHandler::setActiveUAS(UASInterface* uas)
+{
+    // If we were already attached to an autopilot, disconnect it.
+    if (_activeUAS && _activeUAS != uas)
+    {
+        disconnect(_activeUAS, SIGNAL(textMessageReceived(int,int,int,QString)), this, SLOT(handleTextMessage(int,int,int,QString)));
+        _activeUAS = NULL;
+        clearMessages();
+        emit textMessageReceived(NULL);
+    }
     // And now if there's an autopilot to follow, set up the UI.
     if (uas)
     {
-        // Make sure the UI is configured for showing messages.
-        // Note that this call is NOT equivalent to `connectWidget->isVisible()`.
-        if (!connectWidget->isHidden())
-        {
-            connectWidget->hide();
-            ui->plainTextEdit->show();
-        }
-
-        // And connect to the new UAS.
+        // Connect to the new UAS.
+        clearMessages();
+        _activeUAS = uas;
         connect(uas, SIGNAL(textMessageReceived(int,int,int,QString)), this, SLOT(handleTextMessage(int,int,int,QString)));
-        activeUAS = uas;
-    }
-    // But if there's no new autopilot, restore the connect button.
-    else
-    {
-        connectWidget->show();
-        ui->plainTextEdit->hide();
     }
 }
 
-void QGCMessageView::handleTextMessage(int uasid, int compId, int severity, QString text)
+void UASMessageHandler::handleTextMessage(int uasid, int compId, int severity, QString text)
 {
-    QPlainTextEdit *msgWidget = ui->plainTextEdit;
-    (void)uasid; // Unused variable voided.
-    // Turn off updates while we're appending content to avoid breaking the autoscroll behavior
-    msgWidget->setUpdatesEnabled(false);
-    QScrollBar *scroller = msgWidget->verticalScrollBar();
+    Q_UNUSED(uasid);
 
     // Color the output depending on the message severity. We have 3 distinct cases:
     // 1: If we have an ERROR or worse, make it bigger, bolder, and highlight it red.
     // 2: If we have a warning or notice, just make it bold and color it orange.
     // 3: Otherwise color it the standard color, white.
 
-    // So first deteremine the styling based on the severity.
+    // So first determine the styling based on the severity.
     QString style;
     switch (severity)
     {
@@ -142,11 +145,12 @@ void QGCMessageView::handleTextMessage(int uasid, int compId, int severity, QStr
         break;
     }
 
-    // Finally append the properly-styled text with a timestamp.
+    // Finally preppend the properly-styled text with a timestamp.
     QString dateString = QDateTime::currentDateTime().toString("hh:mm:ss.zzz");
-    msgWidget->appendHtml(QString("<p style=\"color:#CCCCCC\">[%2 - COMP:%3]<font style=\"%1\">%4 %5</font></p>").arg(style).arg(dateString).arg(compId).arg(severityText).arg(text));
-
-    // Ensure text area scrolls correctly
-    scroller->setValue(scroller->maximum());
-    msgWidget->setUpdatesEnabled(true);
+    UASMessage* message = new UASMessage(compId, severity, text);
+    message->_setFormatedText(QString("<p style=\"color:#CCCCCC\">[%2 - COMP:%3]<font style=\"%1\">%4 %5</font></p>").arg(style).arg(dateString).arg(compId).arg(severityText).arg(text));
+    _mutex.lock();
+    _messages.append(message);
+    _mutex.unlock();
+    emit textMessageReceived(message);
 }

src/uas/UASMessageHandler.h

+/*=====================================================================
+
+QGroundControl Open Source Ground Control Station
+
+(c) 2009 - 2011 QGROUNDCONTROL PROJECT <http://www.qgroundcontrol.org>
+
+This file is part of the QGROUNDCONTROL project
+
+    QGROUNDCONTROL is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    QGROUNDCONTROL is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with QGROUNDCONTROL. If not, see <http://www.gnu.org/licenses/>.
+
+======================================================================*/
+
+/*!
+ * @file
+ *   @brief Message Handler
+ *   @author Gus Grubba <mavlink@grubba.com>
+ */
+
+#ifndef QGCMESSAGEHANDLER_H
+#define QGCMESSAGEHANDLER_H
+
+#include <QObject>
+#include <QVector>
+#include <QMutex>
+
+#include "QGCSingleton.h"
+
+class UASInterface;
+class UASMessageHandler;
+
+/*!
+ * @class UASMessage
+ * @brief Message element
+ */
+class UASMessage
+{
+    friend class UASMessageHandler;
+public:
+    /**
+     * @brief Get message source component ID
+     */
+    int getComponentID()        { return _compId; }
+    /**
+     * @brief Get message severity (from MAV_SEVERITY_XXX enum)
+     */
+    int getSeverity()           { return _severity; }
+    /**
+     * @brief Get message text (e.g. "[pm] sending list")
+     */
+    QString getText()           { return _text; }
+    /**
+     * @brief Get (html) formatted text (in the form: "[11:44:21.137 - COMP:50] Info: [pm] sending list")
+     */
+    QString getFormatedText()   { return _formatedText; }
+private:
+    UASMessage(int componentid, int severity, QString text);
+    void _setFormatedText(const QString formatedText) { _formatedText = formatedText; }
+    int _compId;
+    int _severity;
+    QString _text;
+    QString _formatedText;
+};
+
+class UASMessageHandler : public QGCSingleton
+{
+    Q_OBJECT
+    DECLARE_QGC_SINGLETON(UASMessageHandler, UASMessageHandler)
+public:
+    explicit UASMessageHandler(QObject *parent = 0);
+    ~UASMessageHandler();
+    /**
+     * @brief Locks access to the message list
+     */
+    void lockAccess()   {_mutex.lock(); }
+    /**
+     * @brief Unlocks access to the message list
+     */
+    void unlockAccess() {_mutex.unlock(); }
+    /**
+     * @brief Access to the message list
+     */
+    const QVector<UASMessage*>& messages() { return _messages; }
+    /**
+     * @brief Clear messages
+     */
+    void clearMessages();
+public slots:
+    /**
+     * @brief Set currently active UAS
+     * @param uas The current active UAS
+     */
+    void setActiveUAS(UASInterface* uas);
+    /**
+     * @brief Handle text message from current active UAS
+     * @param uasid UAS Id
+     * @param componentid Component Id
+     * @param severity Message severity
+     * @param text Message Text
+     */
+    void handleTextMessage(int uasid, int componentid, int severity, QString text);
+signals:
+    /**
+     * @brief Sent out when new message arrives
+     * @param message A pointer to the message. NULL if resetting (new UAS assigned)
+     */
+    void textMessageReceived(UASMessage* message);
+private:
+    // Stores the UAS that we're currently receiving messages from.
+    UASInterface* _activeUAS;
+    QVector<UASMessage*> _messages;
+    QMutex _mutex;
+};
+
+#endif // QGCMESSAGEHANDLER_H

src/ui/QGCTabbedInfoView.cpp

@@ -3,7 +3,7 @@
 QGCTabbedInfoView::QGCTabbedInfoView(QWidget *parent) : QWidget(parent)
 {
     ui.setupUi(this);
-    messageView = new QGCMessageView(this);
+    messageView = new UASMessageViewWidget(this);
     //actionsWidget = new UASActionsWidget(this);
     quickView = new UASQuickView(this);
     //rawView = new UASRawStatusView(this);

src/ui/QGCTabbedInfoView.h

@@ -4,7 +4,7 @@
 #include <QWidget>
 #include "ui_QGCTabbedInfoView.h"
 #include "MAVLinkDecoder.h"
-#include "QGCMessageView.h"
+#include "UASMessageView.h"
 #include "UASQuickView.h"
 #include "UASRawStatusView.h"
 class QGCTabbedInfoView : public QWidget
@@ -18,7 +18,7 @@ public:
 private:
     MAVLinkDecoder *m_decoder;
     Ui::QGCTabbedInfoView ui;
-    QGCMessageView *messageView;
+    UASMessageViewWidget *messageView;
     UASQuickView *quickView;
     UASRawStatusView *rawView;
 };

src/ui/QGCToolBar.cc

@@ -31,6 +31,26 @@ This file is part of the QGROUNDCONTROL project
 #include "UASManager.h"
 #include "MainWindow.h"
 #include "QGCApplication.h"
+#include "UASMessageView.h"
+#include "UASMessageHandler.h"
+
+// Label class that sends mouse hover events
+class QCGHoverLabel : public QLabel
+{
+public:
+    QCGHoverLabel(QGCToolBar* toolBar) : QLabel(toolBar)
+    {
+        _toolBar = toolBar;
+    }
+protected:
+    void enterEvent(QEvent* event)
+    {
+        Q_UNUSED(event);
+        _toolBar->enterMessageLabel();
+    }
+private:
+    QGCToolBar* _toolBar;
+};
 
 QGCToolBar::QGCToolBar(QWidget *parent) :
     QToolBar(parent),
@@ -47,6 +67,7 @@ QGCToolBar::QGCToolBar(QWidget *parent) :
     _linkMgr(LinkManager::instance()),
     _linkCombo(NULL),
     _linkComboAction(NULL),
+    _rollDownMessages(NULL),
     _linksConnected(false),
     _linkSelected(false)
 {
@@ -148,7 +169,7 @@ void QGCToolBar::createUI()
     toolBarWpLabel->setAlignment(Qt::AlignCenter);
     toolBarWpAction = addWidget(toolBarWpLabel);
 
-    toolBarMessageLabel = new QLabel(this);
+    toolBarMessageLabel = new QCGHoverLabel(this);
     toolBarMessageLabel->setToolTip(tr("Most recent system message"));
     toolBarMessageLabel->setObjectName("toolBarMessageLabel");
     toolBarMessageAction = addWidget(toolBarMessageLabel);
@@ -413,7 +434,11 @@ void QGCToolBar::updateView()
         if (QGC::groundTimeMilliseconds() - lastSystemMessageTimeMs < 15000) {
             toolBarMessageLabel->setText(QString("%1").arg(lastSystemMessage));
         } else {
-            toolBarMessageLabel->clear();
+            if(UASMessageHandler::instance()->messages().count()) {
+                toolBarMessageLabel->setText(tr("Messages"));
+            } else {
+                toolBarMessageLabel->setText(tr("No Messages"));
+            }
         }
     }
 
@@ -677,15 +702,6 @@ void QGCToolBar::_disconnectFromMenu(bool checked)
     _linkMgr->disconnectLink(link);
 }
 
-void QGCToolBar::clearStatusString()
-{
-    if (toolBarMessageLabel->text().length() > 0)
-    {
-        lastSystemMessage = "";
-        changed = true;
-    }
-}
-
 void QGCToolBar::_linkComboActivated(int index)
 {
     int type = _linkCombo->itemData(index).toInt();
@@ -721,3 +737,28 @@ void QGCToolBar::_updateConfigurations()
         _linkSelected = false;
     }
 }
+
+/**
+ * @brief Mouse entered Message label area
+ */
+void QGCToolBar::enterMessageLabel()
+{
+    // If not already there and messages are actually present
+    if(!_rollDownMessages && UASMessageHandler::instance()->messages().count())
+    {
+        QPoint p = toolBarMessageLabel->mapToGlobal(QPoint(0,0));
+        _rollDownMessages = new UASMessageViewRollDown(MainWindow::instance(),this);
+        _rollDownMessages->setAttribute(Qt::WA_DeleteOnClose);
+        _rollDownMessages->move(mapFromGlobal(p));
+        _rollDownMessages->setMinimumSize(360,200);
+        _rollDownMessages->show();
+    }
+}
+
+/**
+ * @brief Mouse left message drop down list area (and closed it)
+ */
+void QGCToolBar::leaveMessageView()
+{
+    _rollDownMessages = NULL;
+}

src/ui/QGCToolBar.h

@@ -37,6 +37,8 @@ This file is part of the QGROUNDCONTROL project
 #include "SerialLink.h"
 #include "LinkManager.h"
 
+class UASMessageViewRollDown;
+
 class QGCToolBar : public QToolBar
 {
     Q_OBJECT
@@ -45,6 +47,14 @@ public:
     explicit QGCToolBar(QWidget* parent = 0);
     void setPerspectiveChangeActions(const QList<QAction*> &action);
     void setPerspectiveChangeAdvancedActions(const QList<QAction*> &action);
+    /**
+     * @brief Mouse entered Message label area
+     */
+    void enterMessageLabel();
+    /**
+     * @brief Mouse left message drop down list area (and closed it)
+     */
+    void leaveMessageView();
 
 public slots:
     /** @brief Set the system that is currently displayed by this widget */
@@ -71,8 +81,6 @@ public slots:
     void updateView();
     /** @brief Update connection timeout time */
     void heartbeatTimeout(bool timeout, unsigned int ms);
-    /** @brief Clear status string */
-    void clearStatusString();
     /** @brief Set an activity action as checked in menu */
     void advancedActivityTriggered(QAction* action);
 
@@ -130,6 +138,8 @@ private:
     QComboBox*  _linkCombo;
     QAction*    _linkComboAction;
 
+    UASMessageViewRollDown* _rollDownMessages;
+
     QPushButton*    _connectButton;
     bool            _linksConnected;
     bool            _linkSelected;      // User selected a link. Stop autoselecting it.

src/ui/uas/QGCMessageView.h

-#ifndef QGCMESSAGEVIEW_H
-#define QGCMESSAGEVIEW_H
-
-#include <QWidget>
-#include <UASInterface.h>
-#include <QVBoxLayout>
-#include <QAction>
-#include "QGCUnconnectedInfoWidget.h"
-
-namespace Ui {
-class QGCMessageView;
-}
-
-class QGCMessageView : public QWidget
-{
-    Q_OBJECT
-    
-public:
-    explicit QGCMessageView(QWidget *parent = 0);
-    ~QGCMessageView();
-
-public slots:
-    /**
-     * @brief Set currently active UAS
-     * @param uas the current active UAS
-     */
-    void setActiveUAS(UASInterface* uas);
-    /**
-     * @brief Handle text message from current active UAS
-     * @param uasid
-     * @param componentid
-     * @param severity
-     * @param text
-     */
-    void handleTextMessage(int uasid, int componentid, int severity, QString text);
-
-protected:
-    // Stores the UAS that we're currently receiving messages from.
-    UASInterface* activeUAS;
-    // Stores the connect widget that is displayed when no UAS is active.
-    QGCUnconnectedInfoWidget* connectWidget;
-    
-private:
-    Ui::QGCMessageView *ui;
-};
-
-#endif // QGCMESSAGEVIEW_H

src/ui/uas/UASMessageView.cc

+/*=====================================================================
+
+QGroundControl Open Source Ground Control Station
+
+(c) 2009 - 2011 QGROUNDCONTROL PROJECT <http://www.qgroundcontrol.org>
+
+This file is part of the QGROUNDCONTROL project
+
+    QGROUNDCONTROL is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    QGROUNDCONTROL is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with QGROUNDCONTROL. If not, see <http://www.gnu.org/licenses/>.
+
+======================================================================*/
+
+#include <QMenu>
+#include <QScrollBar>
+
+#include "QGCToolBar.h"
+#include "UASMessageView.h"
+#include "QGCUnconnectedInfoWidget.h"
+#include "UASMessageHandler.h"
+#include "ui_UASMessageView.h"
+
+/*-------------------------------------------------------------------------------------
+  UASMessageView
+-------------------------------------------------------------------------------------*/
+
+UASMessageView::UASMessageView(QWidget *parent) :
+    QWidget(parent),
+    _ui(new Ui::UASMessageView)
+{
+    _ui->setupUi(this);
+}
+
+UASMessageView::~UASMessageView()
+{
+    delete _ui;
+}
+
+/*-------------------------------------------------------------------------------------
+  UASMessageViewWidget
+-------------------------------------------------------------------------------------*/
+
+UASMessageViewWidget::UASMessageViewWidget(QWidget *parent)
+    : UASMessageView(parent)
+    , _unconnectedWidget(NULL)
+{
+    setStyleSheet("QPlainTextEdit { border: 0px }");
+    // Construct initial widget
+    _unconnectedWidget = new QGCUnconnectedInfoWidget(this);
+    ui()->horizontalLayout->addWidget(_unconnectedWidget);
+    ui()->plainTextEdit->hide();
+    // Enable the right-click menu for the text editor. This works because the plainTextEdit
+    // widget has its context menu policy set to its actions list. So any actions we add
+    // to this widget's action list will be automatically displayed.
+    // We only have the clear action right now.
+    QAction* clearAction = new QAction(tr("Clear Messages"), this);
+    connect(clearAction, &QAction::triggered, this, &UASMessageViewWidget::clearMessages);
+    ui()->plainTextEdit->addAction(clearAction);
+    // Connect message handler
+    connect(UASMessageHandler::instance(), &UASMessageHandler::textMessageReceived, this, &UASMessageViewWidget::handleTextMessage);
+}
+
+UASMessageViewWidget::~UASMessageViewWidget()
+{
+
+}
+
+void UASMessageViewWidget::clearMessages()
+{
+    ui()->plainTextEdit->clear();
+    UASMessageHandler::instance()->clearMessages();
+}
+
+void UASMessageViewWidget::handleTextMessage(UASMessage *message)
+{
+    // Reset
+    if(!message) {
+        ui()->plainTextEdit->clear();
+        _unconnectedWidget->show();
+        ui()->plainTextEdit->hide();
+    } else {
+        // Make sure the UI is configured for showing messages.
+        // Note that this call is NOT equivalent to `_unconnectedWidget->isVisible()`.
+        if (!_unconnectedWidget->isHidden())
+        {
+            _unconnectedWidget->hide();
+            ui()->plainTextEdit->show();
+        }
+        QPlainTextEdit *msgWidget = ui()->plainTextEdit;
+        // Turn off updates while we're appending content to avoid breaking the autoscroll behavior
+        msgWidget->setUpdatesEnabled(false);
+        QScrollBar *scroller = msgWidget->verticalScrollBar();
+        msgWidget->appendHtml(message->getFormatedText());
+        // Ensure text area scrolls correctly
+        scroller->setValue(scroller->maximum());
+        msgWidget->setUpdatesEnabled(true);
+    }
+}
+
+/*-------------------------------------------------------------------------------------
+  UASMessageViewRollDown
+-------------------------------------------------------------------------------------*/
+
+UASMessageViewRollDown::UASMessageViewRollDown(QWidget *parent, QGCToolBar *toolBar)
+    : UASMessageView(parent)
+{
+    _toolBar = toolBar;
+    setAttribute(Qt::WA_TranslucentBackground);
+    setStyleSheet("background-color: rgba(0%,0%,0%,80%); border: 2px;");
+    QPlainTextEdit *msgWidget = ui()->plainTextEdit;
+    // Init Messages
+    UASMessageHandler::instance()->lockAccess();
+    msgWidget->setUpdatesEnabled(false);
+    QVector<UASMessage*> messages = UASMessageHandler::instance()->messages();
+    for(int i = 0; i < messages.count(); i++) {
+        msgWidget->appendHtml(messages.at(i)->getFormatedText());
+    }
+    QScrollBar *scroller = msgWidget->verticalScrollBar();
+    scroller->setValue(scroller->maximum());
+    msgWidget->setUpdatesEnabled(true);
+    connect(UASMessageHandler::instance(), &UASMessageHandler::textMessageReceived, this, &UASMessageViewRollDown::handleTextMessage);
+    UASMessageHandler::instance()->unlockAccess();
+}
+
+UASMessageViewRollDown::~UASMessageViewRollDown()
+{
+
+}
+
+void UASMessageViewRollDown::handleTextMessage(UASMessage *message)
+{
+    // Reset
+    if(!message) {
+        ui()->plainTextEdit->clear();
+    } else {
+        QPlainTextEdit *msgWidget = ui()->plainTextEdit;
+        // Turn off updates while we're appending content to avoid breaking the autoscroll behavior
+        msgWidget->setUpdatesEnabled(false);
+        QScrollBar *scroller = msgWidget->verticalScrollBar();
+        msgWidget->appendHtml(message->getFormatedText());
+        // Ensure text area scrolls correctly
+        scroller->setValue(scroller->maximum());
+        msgWidget->setUpdatesEnabled(true);
+    }
+}
+
+void UASMessageViewRollDown::leaveEvent(QEvent * event)
+{
+    Q_UNUSED(event);
+    _toolBar->leaveMessageView();
+    close();
+}

src/ui/uas/UASMessageView.h

+/*=====================================================================
+
+QGroundControl Open Source Ground Control Station
+
+(c) 2009 - 2011 QGROUNDCONTROL PROJECT <http://www.qgroundcontrol.org>
+
+This file is part of the QGROUNDCONTROL project
+
+    QGROUNDCONTROL is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    QGROUNDCONTROL is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with QGROUNDCONTROL. If not, see <http://www.gnu.org/licenses/>.
+
+======================================================================*/
+
+#ifndef QGCMESSAGEVIEW_H
+#define QGCMESSAGEVIEW_H
+
+#include <QWidget>
+#include <UASInterface.h>
+#include <QVBoxLayout>
+#include <QAction>
+#include "QGCUnconnectedInfoWidget.h"
+
+class UASMessage;
+class QGCToolBar;
+
+namespace Ui {
+class UASMessageView;
+}
+
+// Message View base class
+class UASMessageView : public QWidget
+{
+    Q_OBJECT
+    
+public:
+    explicit UASMessageView(QWidget *parent = 0);
+    virtual ~UASMessageView();
+    Ui::UASMessageView* ui() { return _ui; }
+private:
+    Ui::UASMessageView* _ui;
+};
+
+// Message View Widget (used in the Info View tabbed Widget)
+class UASMessageViewWidget : public UASMessageView
+{
+    Q_OBJECT
+public:
+    explicit UASMessageViewWidget(QWidget *parent = 0);
+    ~UASMessageViewWidget();
+public slots:
+    void handleTextMessage(UASMessage* message);
+    void clearMessages();
+private:
+    QGCUnconnectedInfoWidget* _unconnectedWidget;
+};
+
+// Roll down Message View
+class UASMessageViewRollDown : public UASMessageView
+{
+    Q_OBJECT
+public:
+    explicit UASMessageViewRollDown(QWidget *parent, QGCToolBar* toolBar);
+    ~UASMessageViewRollDown();
+public slots:
+    void handleTextMessage(UASMessage* message);
+protected:
+    void leaveEvent(QEvent* event);
+private:
+    QGCToolBar* _toolBar;
+};
+
+#endif // QGCMESSAGEVIEW_H

src/ui/uas/QGCMessageView.ui → src/ui/uas/UASMessageView.ui

 <?xml version="1.0" encoding="UTF-8"?>
 <ui version="4.0">
- <class>QGCMessageView</class>
- <widget class="QWidget" name="QGCMessageView">
+ <class>UASMessageView</class>
+ <widget class="QWidget" name="UASMessageView">
   <property name="geometry">
    <rect>
     <x>0</x>
@@ -10,6 +10,12 @@
     <height>249</height>
    </rect>
   </property>
+  <property name="sizePolicy">
+   <sizepolicy hsizetype="Expanding" vsizetype="Expanding">
+    <horstretch>0</horstretch>
+    <verstretch>0</verstretch>
+   </sizepolicy>
+  </property>
   <property name="contextMenuPolicy">
    <enum>Qt::NoContextMenu</enum>
   </property>
@@ -18,19 +24,25 @@
   </property>
   <layout class="QHBoxLayout" name="horizontalLayout">
    <property name="leftMargin">
-    <number>0</number>
+    <number>4</number>
    </property>
    <property name="topMargin">
     <number>8</number>
    </property>
    <property name="rightMargin">
-    <number>0</number>
+    <number>4</number>
    </property>
    <property name="bottomMargin">
-    <number>0</number>
+    <number>4</number>
    </property>
    <item>
     <widget class="QPlainTextEdit" name="plainTextEdit">
+     <property name="minimumSize">
+      <size>
+       <width>0</width>
+       <height>0</height>
+      </size>
+     </property>
      <property name="contextMenuPolicy">
       <enum>Qt::ActionsContextMenu</enum>
      </property>