Add two AIs: They are both designed to do the same. Spin until they see a tank

and then fire. One of them has an error, which causes it to enter its error
state. The errorstate example has been changed to handle this by disabling
the tank. The rest of the tanks will keep working.

7 files changed, 80 insertions, 26 deletions

diff --git a/examples/statemachine/errorstate/gameitem.h b/examples/statemachine/errorstate/gameitem.h
index 6ca32b7..9808706 100644
--- a/examples/statemachine/errorstate/gameitem.h
+++ b/examples/statemachine/errorstate/gameitem.h
@@ -7,13 +7,8 @@ class QLineF;
 class GameItem: public QGraphicsItem
 {
 public:
-    enum { Type = UserType + 1 };
-
-    int type() const { return Type; }
     virtual void idle(qreal elapsed) = 0;
 
-    virtual void hitByRocket() = 0;
-
 protected:
     QPointF tryMove(const QPointF &requestedPosition, QLineF *collidedLine = 0, 
         QGraphicsItem **collidedItem = 0) const;
diff --git a/examples/statemachine/errorstate/mainwindow.cpp b/examples/statemachine/errorstate/mainwindow.cpp
index e04ca94..daf7be0 100644
--- a/examples/statemachine/errorstate/mainwindow.cpp
+++ b/examples/statemachine/errorstate/mainwindow.cpp
@@ -105,6 +105,7 @@ void MainWindow::init()
 
     QAction *addTankAction = menuBar()->addAction("&Add tank");   
     QAction *runGameAction = menuBar()->addAction("&Run game");    
+    runGameAction->setObjectName("runGameAction");
     QAction *stopGameAction = menuBar()->addAction("&Stop game");        
     menuBar()->addSeparator();
     QAction *quitAction = menuBar()->addAction("&Quit");
@@ -112,9 +113,7 @@ void MainWindow::init()
     connect(addTankAction, SIGNAL(triggered()), this, SLOT(addTank()));
     connect(quitAction, SIGNAL(triggered()), this, SLOT(close()));
         
-    m_machine = new QStateMachine(this);
-    m_machine->setGlobalRestorePolicy(QStateMachine::RestoreProperties);
-    
+    m_machine = new QStateMachine(this);    
     QState *stoppedState = new QState(m_machine->rootState());        
     stoppedState->setObjectName("stoppedState");
     stoppedState->assignProperty(runGameAction, "enabled", true);
@@ -168,7 +167,11 @@ void MainWindow::runStep()
             qreal elapsedSecs = elapsed / 1000.0;
             QList<QGraphicsItem *> items = m_scene->items();
             foreach (QGraphicsItem *item, items) {
-                GameItem *gameItem = qgraphicsitem_cast<GameItem *>(item);
+                // ###
+                GameItem *gameItem = qgraphicsitem_cast<TankItem *>(item);
+                if (gameItem == 0)
+                    gameItem = qgraphicsitem_cast<RocketItem *>(item);
+
                 if (gameItem != 0)
                     gameItem->idle(elapsedSecs);
             }
@@ -206,7 +209,13 @@ void MainWindow::addTank()
             emit mapFull();
         
         QState *region = new QState(m_runningState);
-        region->setInitialState(plugin->create(region, tankItem));
+        QState *pluginState = plugin->create(region, tankItem);
+        region->setInitialState(pluginState);
+
+        // If the plugin has an error it is disabled
+        QState *errorState = new QState(region);
+        errorState->assignProperty(tankItem, "enabled", false);
+        pluginState->setErrorState(errorState);
     }
 }
 
diff --git a/examples/statemachine/errorstate/plugin.h b/examples/statemachine/errorstate/plugin.h
index 1ac7e0f..69b9574 100644
--- a/examples/statemachine/errorstate/plugin.h
+++ b/examples/statemachine/errorstate/plugin.h
@@ -1,6 +1,8 @@
 #ifndef PLUGIN_H
 #define PLUGIN_H
 
+#include <QtPlugin>
+
 class QState;
 class Tank;
 class Plugin
diff --git a/examples/statemachine/errorstate/rocketitem.cpp b/examples/statemachine/errorstate/rocketitem.cpp
index de9eef7..85d436b 100644
--- a/examples/statemachine/errorstate/rocketitem.cpp
+++ b/examples/statemachine/errorstate/rocketitem.cpp
@@ -1,4 +1,5 @@
 #include "rocketitem.h"
+#include "tankitem.h"
 
 #include <QPainter>
 #include <QGraphicsScene>
@@ -25,10 +26,6 @@ void RocketItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *, QWid
     painter->drawEllipse(boundingRect());
 }
 
-void RocketItem::hitByRocket()
-{
-}
-
 void RocketItem::idle(qreal elapsed)
 {
     qreal dist = elapsed * speed();
@@ -51,8 +48,8 @@ void RocketItem::idle(qreal elapsed)
     if (requestedPosition == nextPosition) {
         setPos(nextPosition);
     } else {
-        if (GameItem *gameItem = qgraphicsitem_cast<GameItem *>(collidedItem))
-            gameItem->hitByRocket();
+        if (TankItem *tankItem = qgraphicsitem_cast<TankItem *>(collidedItem))
+            tankItem->hitByRocket();
         
         scene()->removeItem(this);
         delete this;
diff --git a/examples/statemachine/errorstate/rocketitem.h b/examples/statemachine/errorstate/rocketitem.h
index 9805a8a..b055b0a 100644
--- a/examples/statemachine/errorstate/rocketitem.h
+++ b/examples/statemachine/errorstate/rocketitem.h
@@ -6,13 +6,14 @@
 class RocketItem: public GameItem
 {
 public:
+    enum { Type = UserType + 2 };
+
     RocketItem();
 
+    int type() const { return Type; }
     virtual void idle(qreal elapsed);
     qreal speed() const { return 100.0; }
     void setDirection(qreal direction) { m_direction = direction; }
-
-    void hitByRocket();
     
 protected:
     virtual void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget);
diff --git a/examples/statemachine/errorstate/tankitem.cpp b/examples/statemachine/errorstate/tankitem.cpp
index 814de2b..705623c 100644
--- a/examples/statemachine/errorstate/tankitem.cpp
+++ b/examples/statemachine/errorstate/tankitem.cpp
@@ -85,17 +85,25 @@ private:
     bool m_reverse;
 };
 
-TankItem::TankItem(QObject *parent) : Tank(parent), m_currentAction(0), m_currentDirection(0.0)
+TankItem::TankItem(QObject *parent) 
+    : Tank(parent), m_currentAction(0), m_currentDirection(0.0), m_enabled(true)
 {
     connect(this, SIGNAL(fireCannon()), this, SIGNAL(actionCompleted()));
 }
 
 void TankItem::idle(qreal elapsed)
 {
-    if (m_currentAction != 0) {
-        if (!m_currentAction->apply(elapsed)) {
-            setAction(0);
-            emit actionCompleted();
+    if (m_enabled) {
+        if (m_currentAction != 0) {
+            if (!m_currentAction->apply(elapsed)) {
+                setAction(0);
+                emit actionCompleted();
+            }
+
+            QGraphicsItem *item = 0;
+            qreal distance = distanceToObstacle(&item);
+            if (TankItem *tankItem = qgraphicsitem_cast<TankItem *>(item))
+                emit tankSpotted(tankItem->direction(), distance);        
         }
     }
 }
@@ -176,6 +184,17 @@ void TankItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *, QWidge
                                    QPointF(brect.right() - 2.0, brect.bottom()));
     painter->fillRect(rightTrackRect, Qt::darkYellow);
     painter->drawRect(rightTrackRect);
+
+    if (!m_enabled) {
+        painter->setPen(QPen(Qt::red, 5));
+
+        painter->drawEllipse(brect);
+
+        QPainterPath path;
+        path.addEllipse(brect);
+        painter->setClipPath(path);
+        painter->drawLine(brect.topRight(), brect.bottomLeft());
+    }
 }
 
 QRectF TankItem::boundingRect() const
@@ -195,11 +214,32 @@ void TankItem::setDirection(qreal newDirection)
     rotate(diff);
 }
 
-qreal TankItem::distanceToObstacle() const
+qreal TankItem::distanceToObstacle(QGraphicsItem **obstacle) const
 {
-    // ###
+    qreal dist = sqrt(pow(scene()->sceneRect().width(), 2) + pow(scene()->sceneRect().height(), 2));
+
+    qreal a = m_currentDirection * M_PI / 180.0;
+
+    qreal yd = dist * sin(a);
+    qreal xd = dist * sin(M_PI / 2.0 - a);
 
-    return 0.0;
+    QPointF requestedPosition = pos() + QPointF(xd, yd);
+    QGraphicsItem *collidedItem = 0;
+    QPointF nextPosition = tryMove(requestedPosition, 0, &collidedItem);
+    if (collidedItem != 0) {
+        if (obstacle != 0)
+            *obstacle = collidedItem;        
+        
+        QPointF d = nextPosition - pos();
+        return sqrt(pow(d.x(), 2) + pow(d.y(), 2));
+    } else {
+        return 0.0;
+    }
+}
+
+qreal TankItem::distanceToObstacle() const
+{
+    return distanceToObstacle(0);
 }
 
 
diff --git a/examples/statemachine/errorstate/tankitem.h b/examples/statemachine/errorstate/tankitem.h
index c9e0d22..e598cfd 100644
--- a/examples/statemachine/errorstate/tankitem.h
+++ b/examples/statemachine/errorstate/tankitem.h
@@ -10,8 +10,13 @@ class Action;
 class TankItem: public Tank, public GameItem
 {
     Q_OBJECT
+    Q_PROPERTY(bool enabled READ enabled WRITE setEnabled)
 public:
+    enum { Type = UserType + 1 };
+
     TankItem(QObject *parent = 0);
+
+    int type() const { return Type; }
     
     virtual void moveForwards(qreal length);
     virtual void moveBackwards(qreal length);
@@ -19,6 +24,7 @@ public:
     virtual void stop();
     virtual qreal direction() const;
     virtual qreal distanceToObstacle() const;
+    virtual qreal distanceToObstacle(QGraphicsItem **item) const;
 
     void setColor(const QColor &color) { m_color = color; }
     QColor color() const { return m_color; }
@@ -33,6 +39,9 @@ public:
 
     void hitByRocket();
 
+    void setEnabled(bool b) { m_enabled = b; }
+    bool enabled() const { return m_enabled; }
+
 signals:
     virtual void fireCannon();
 
@@ -46,6 +55,7 @@ private:
     Action *m_currentAction;
     qreal m_currentDirection;
     QColor m_color;
+    bool m_enabled;
 };
 
 #endif