[server] Rewrite positioning logic of connection frames

This fixes sevceral bugs:
* Frames moved into virtually expanded area (for keeping aspect ratio)
  could be out of bounds after a window resize before
* Finding a free slot to place a frame was slightly sped up
* Finding a free slot is not used when loading a room layout, as
  it was (still is) pretty sluggish for the user
* Snap to grid worked incorrectly, did not pick closest grid position

1 files changed, 89 insertions, 73 deletions

diff --git a/src/server/mainwindow/mainwindow.cpp b/src/server/mainwindow/mainwindow.cpp
index cb2e4da..87ecca4 100644
--- a/src/server/mainwindow/mainwindow.cpp
+++ b/src/server/mainwindow/mainwindow.cpp
@@ -217,25 +217,23 @@ MainWindow::~MainWindow()
 	delete ui;
 }
 
-/** Euclidean distance (why is this not implemented in QPoint?) */
-float distance(QPoint a, QPoint b)
+/** Squared euclidean distance (why is this not implemented in QPoint?) */
+int distance(QPoint a, QPoint b)
 {
-	int dx = a.x() - b.x();
-	int dy = a.y() - b.y();
-	int sum = dx * dx + dy * dy;
-	return sqrt((float) sum);
+	const int dx = a.x() - b.x();
+	const int dy = a.y() - b.y();
+	const int sum = dx * dx + dy * dy;
+	return sum;
 }
 
-float distance(QPointF a, QPointF b)
+int distance(QPointF a, QPointF b)
 {
-	int dx = a.x() - b.x();
-	int dy = a.y() - b.y();
-	int sum = dx * dx + dy * dy;
-	return sqrt(sum);
+	const int dx = a.x() - b.x();
+	const int dy = a.y() - b.y();
+	const int sum = dx * dx + dy * dy;
+	return sum;
 }
 
-
-
 /***************************************************************************//**
  * \brief: find the closest available frame.
  *
@@ -251,6 +249,14 @@ float distance(QPointF a, QPointF b)
  */
 QPoint MainWindow::closestFreeSlot(QPoint preferredPixels, ConnectionFrame* toIgnore)
 {
+	const bool pickFirstOne = ( preferredPixels == QPoint(-1, -1) );
+	if (!pickFirstOne && toIgnore != NULL) {
+		// Check if we're already in the desired location and skip all the checks
+		QPoint desired = QPoint(preferredPixels.x() / getTileWidthPx(), preferredPixels.y() / getTileHeightPx());
+		if (desired == toIgnore->getGridPosition()) {
+			return desired;
+		}
+	}
 	const QSize& clientSize = serverApp->getCurrentRoom()->clientSize;
 	bool grid[_tilesX][_tilesY];
 	memset(grid, 0, sizeof(bool) * _tilesX * _tilesY); /* set everything to false */
@@ -260,7 +266,7 @@ QPoint MainWindow::closestFreeSlot(QPoint preferredPixels, ConnectionFrame* toIg
 
 		if (*it == toIgnore) { continue; }
 
-		const QPoint& p = (*it)->getGridPosition();
+		const QPoint p = (*it)->getGridPosition();
 
 		for (int x = p.x(); x < p.x() + clientSize.width(); x++) {
 			for (int y = p.y(); y < p.y() + clientSize.height(); y++) {
@@ -283,18 +289,23 @@ QPoint MainWindow::closestFreeSlot(QPoint preferredPixels, ConnectionFrame* toIg
 					}
 				}
 			}
-endLoop:
-			if (isFree) { freePositions << QPoint(x, y); }
+endLoop: ;
+			if (isFree) {
+				freePositions << QPoint(x, y);
+				if (pickFirstOne) {
+					goto endSearch;
+				}
+			}
 		}
 	}
+endSearch: ;
 	/* among all the free positions, find the closest */
-	float min_distance = 10000;
-	QPoint bestPosition = QPoint(-1, -1);
+	float min_distance = 1000000;
+	QPoint bestPosition = QPoint(0, 0);
 
 	for (QPoint freePos : freePositions) {
-		QPoint freePosCenter( freePos.x() * getTileWidthPx()  +  getTileWidthPx() * clientSize.width() / 2,
-		                      freePos.y() * getTileHeightPx() + getTileHeightPx() * clientSize.height() / 2);
-		float dist = distance(freePosCenter, preferredPixels);
+		const QPoint freePosPx( freePos.x() * getTileWidthPx(), freePos.y() * getTileHeightPx() );
+		const float dist = distance(freePosPx, preferredPixels);
 		if (dist < min_distance) {
 			min_distance = dist;
 			bestPosition = freePos;
@@ -307,10 +318,7 @@ endLoop:
 void MainWindow::placeFrameInFreeSlot(ConnectionFrame* frame, QPoint preferredPixels)
 {
 	QPoint bestPosition = closestFreeSlot(preferredPixels, frame);
-
 	frame->setGridPosition(bestPosition);
-	QPoint freePosPx(bestPosition.x() * getTileWidthPx(), bestPosition.y() * getTileHeightPx());
-	frame->setCurrentPosition(freePosPx);
 }
 
 /***************************************************************************//**
@@ -321,14 +329,12 @@ void MainWindow::placeFrameInFreeSlot(ConnectionFrame* frame, QPoint preferredPi
  */
 ConnectionFrame* MainWindow::createFrame()
 {
-	// Allocate and resize
-	int width = getTileWidthPx() * serverApp->getCurrentRoom()->clientSize.width();
-	int height = getTileHeightPx() * serverApp->getCurrentRoom()->clientSize.height();
-
-	ConnectionFrame *cf = new ConnectionFrame(ui->frmRoom, width, height);
+	ConnectionFrame *cf = new ConnectionFrame(this, ui->frmRoom);
+	// Move to any free tile
+	placeFrameInFreeSlot(cf);
 	_clientFrames.append(cf);
 	cf->show();
-	connect(cf, SIGNAL(frameMoved(bool, ConnectionFrame *)), this, SLOT(onPlaceFrame(bool, ConnectionFrame *)));
+	connect(cf, SIGNAL(frameMoved(ConnectionFrame *)), this, SLOT(onPlaceFrame(ConnectionFrame *)));
 	connect(cf, SIGNAL(clicked(ConnectionFrame *)), this, SLOT(onFrameClicked(ConnectionFrame *)));
 	return cf;
 }
@@ -339,20 +345,14 @@ ConnectionFrame* MainWindow::createFrame()
  * Also connect signals frameMoved() and clicked() with slots.
  * @return ConnectionFrame*
  */
-ConnectionFrame* MainWindow::createFrame(QString computerId, QPoint pxCoord, QPoint gridPosition)
+ConnectionFrame* MainWindow::createFrame(QString computerId, QPoint gridPosition)
 {
-	// Allocate and resize
-	const Room* room = serverApp->getCurrentRoom();
-	int width = getTileWidthPx() *  (room == NULL ? 1 : room->clientSize.width());
-	int height = getTileHeightPx() * (room == NULL ? 1 : room->clientSize.height());
-
-	ConnectionFrame *cf = new ConnectionFrame(ui->frmRoom, width, height);
+	ConnectionFrame *cf = new ConnectionFrame(this, ui->frmRoom);
 	cf->setComputerId(computerId);
-	cf->setCurrentPosition(pxCoord);
 	cf->setGridPosition(gridPosition);
 	_clientFrames.append(cf);
 	cf->show();
-	connect(cf, SIGNAL(frameMoved(bool, ConnectionFrame *)), this, SLOT(onPlaceFrame(bool, ConnectionFrame *)));
+	connect(cf, SIGNAL(frameMoved(ConnectionFrame *)), this, SLOT(onPlaceFrame(ConnectionFrame *)));
 	connect(cf, SIGNAL(clicked(ConnectionFrame *)), this, SLOT(onFrameClicked(ConnectionFrame *)));
 	return cf;
 }
@@ -480,41 +480,54 @@ AspectStatus checkAspectRatio(const QSize& frameSize, const QSize& gridSize)
  */
 void MainWindow::resizeEvent(QResizeEvent* e)
 {
-	const Room* room = serverApp->getCurrentRoom();
-	const QSize& clientSize = room->clientSize;
-
-	if (ui->frmRoom->size().width() < 100 || ui->frmRoom->size().height() < 100 || _tilesX <= 0 || _tilesY <= 0) { return; }
+	if (ui->frmRoom->size().width() < 100 || ui->frmRoom->size().height() < 100) {
+		return;
+	}
 
+	const Room* room = serverApp->getCurrentRoom();
 	QSize newGridSize = room->gridSize;
+	const QSize& clientSize = room->clientSize;
 
-	/* do we have to add virtual columns? */
-	while (checkAspectRatio(ui->frmRoom->size(), newGridSize) == GRID_TOO_WIDE) {
-		/* add row */
-		newGridSize.setHeight(newGridSize.height() + 1);
-	}
-	while (checkAspectRatio(ui->frmRoom->size(), newGridSize) == GRID_TOO_TALL) {
-		/* add column */
-		newGridSize.setWidth(newGridSize.width() + 1);
+	// Check if any frames have been moved beyond the room dimensions
+	for (auto it = _clientFrames.begin(); it != _clientFrames.end(); ++it) {
+		QPoint bounds = (*it)->getGridPosition();
+		while (bounds.x() + clientSize.width() > newGridSize.width()) {
+			newGridSize += QSize(1, 0);
+		}
+		while (bounds.y() + clientSize.height() > newGridSize.height()) {
+			newGridSize += QSize(0, 1);
+		}
 	}
+
+	/* do we have to add virtual columns or rows? */
+	AspectStatus status;
+	do {
+		status = checkAspectRatio(ui->frmRoom->size(), newGridSize);
+		if (status == GRID_TOO_WIDE) {
+			/* add row */
+			newGridSize += QSize(0, 1);
+		}
+		if (status == GRID_TOO_TALL) {
+			/* add column */
+			newGridSize += QSize(1, 0);
+		}
+	} while (status != GRID_OK);
 	this->_tilesX = newGridSize.width();
 	this->_tilesY = newGridSize.height();
+	const int maxX = _tilesX - clientSize.width();
+	const int maxY = _tilesY - clientSize.height();
 
 	/* Bring back frames which are now out of the screen */
 	for (auto it = _clientFrames.begin(); it != _clientFrames.end(); ++it) {
 		const QPoint gp = (*it)->getGridPosition();
-		if ( gp.x() >= _tilesX || gp.y() >= _tilesY ) {
-			placeFrameInFreeSlot(*it, (*it)->getCurrentPosition());
+		if ( gp.x() > maxX || gp.y() > maxY ) {
+			placeFrameInFreeSlot(*it, (*it)->pos());
 		}
 	}
 
 	/* Resize all connection windows */
 	for (auto it = _clientFrames.begin(); it != _clientFrames.end(); ++it) {
-		int newPosX = (*it)->getGridPosition().x() * getTileWidthPx();
-		int newPosY = (*it)->getGridPosition().y() * getTileHeightPx();
-		QPoint newPos(newPosX, newPosY);
-
-		(*it)->setSize(getTileWidthPx() * clientSize.width(), getTileHeightPx() * clientSize.height());
-		(*it)->move(newPos);
+		(*it)->updateGeometry();
 	}
 
 	/* update background image label */
@@ -607,13 +620,13 @@ void MainWindow::reset()
 * Place frame to from user specified position. Should be called when a
 * connectionFrame is dropped during the "drag-n-drop".
  */
-void MainWindow::onPlaceFrame(bool activateTrash, ConnectionFrame* connectionFrame)
+void MainWindow::onPlaceFrame(ConnectionFrame* connectionFrame)
 {
 	// if (_tilesX <= 0 || _tilesY <= 0) return;
-	const QPoint &preferredPixels = connectionFrame->frameGeometry().center();
+	const QPoint preferredPixels = connectionFrame->pos();
 	placeFrameInFreeSlot(connectionFrame, preferredPixels);
 
-	resizeEvent(NULL);
+	//resizeEvent(NULL);
 }
 
 /***************************************************************************//**
@@ -737,11 +750,9 @@ void MainWindow::reloadCurrentRoom()
 		for (auto it = room->clientPositions.begin(); it != room->clientPositions.end(); ++it) {
 			QString computerId = it.key();
 			QPoint pos = it.value();
-			QPoint pxPos(pos.x() * getTileWidthPx(), pos.y() * getTileHeightPx());
 
-			ConnectionFrame *cf = createFrame(computerId, pxPos, pos);
-			cf->move(cf->getCurrentPosition());
-			onPlaceFrame(false, cf);
+			ConnectionFrame *cf = createFrame(computerId, pos);
+			onPlaceFrame(cf);
 			if (computerId == room->tutorIP) {
 				qDebug() << "set computer with id " << computerId << " as tutor per configuration";
 				if (getTutorFrame() != NULL) {
@@ -808,13 +819,24 @@ void MainWindow::onReloadRoomOk()
 
 int MainWindow::getTileWidthPx() const
 {
+
 	return ui->frmRoom->size().width() / _tilesX;
 }
+
 int MainWindow::getTileHeightPx() const
 {
 	return ui->frmRoom->size().height() / _tilesY;
 }
 
+QRect MainWindow::calcFrameGeometry(ConnectionFrame* frame) const
+{
+	const QPoint pos = frame->getGridPosition();
+	const QSize& clientSize = serverApp->getCurrentRoom()->clientSize;
+	const int w = getTileWidthPx();
+	const int h = getTileHeightPx();
+	return QRect(pos.x() * w, pos.y() * h, w * clientSize.width(), h * clientSize.height());
+}
+
 /***************************************************************************//**
  * Display popup which explains possible actions about the buttons.
  */
@@ -1133,12 +1155,10 @@ void MainWindow::onClientAuthenticated(Client* client)
 
 	// New one, create
 	ConnectionFrame *cf = createFrame();
-	// Move to any free tile
-	placeFrameInFreeSlot(cf);
 	// Assign client instance
 	cf->assignClient(client);
 
-	resizeEvent(NULL); // This is where all the positioning should be
+	//resizeEvent(NULL); // This is where all the positioning should be
 	tellClientCurrentSituation(client);
 	updateExamMode();
 
@@ -1276,10 +1296,6 @@ void MainWindow::onDeleteClient()
 			lockContextButtons();
 			updateExamMode();
 			return;
-		} else {
-			frame->move(frame->getPreviousPosition());
-			updateExamMode();
-			return;
 		}
 	}