Scrolling implemented more correctly

Author: yurii-litvinov

trikGui/motorLever.cpp

@@ -37,7 +37,6 @@ MotorLever::MotorLever(const QString &port, trikControl::MotorInterface &motor,
 	, mPowerStep(10)
 	, mPower(0)
 	, mNameLabel(port)
-	, mPowerLabel("0")
 	, mOnOffLabel(tr("off"))
 {
 	mMotor.powerOff();
@@ -46,23 +45,19 @@ MotorLever::MotorLever(const QString &port, trikControl::MotorInterface &motor,
 	mPowerBar.setMinimum(mMinPower);
 	mPowerBar.setMaximum(mMaxPower);
 	mPowerBar.setValue(0);
-	mPowerBar.setTextVisible(false);
+	mPowerBar.setTextVisible(true);
+	mPowerBar.setFormat("%v");
 
 	mNameLabel.setAlignment(Qt::AlignCenter);
 	mPowerBar.setAlignment(Qt::AlignCenter);
-	mPowerLabel.setAlignment(Qt::AlignCenter);
 	mOnOffLabel.setAlignment(Qt::AlignCenter);
 
-	// mPowerLabel and mOnOffLabel can change their widths during work. It will cause mPowerBar
-	// width change. To prevent it, we set fixed widths for mPowerLabel and mOnOffLabel.
-	// They are equal to maximum widths of the widgets. For mPowerLabel it is when the label text
-	// is "-100", for mOnOffLabel - "off".
-	mPowerLabel.setFixedWidth(40);
+	// mOnOffLabel can change its width during work. It will cause mPowerBar
+	// width change. To prevent it, we set fixed width it.
 	mOnOffLabel.setFixedWidth(48);
 
 	mLayout.addWidget(&mNameLabel);
 	mLayout.addWidget(&mPowerBar);
-	mLayout.addWidget(&mPowerLabel);
 	mLayout.addWidget(&mOnOffLabel);
 	setLayout(&mLayout);
 
@@ -117,7 +112,6 @@ void MotorLever::setPower(int power)
 
 	mPower = power;
 	mPowerBar.setValue(power);
-	mPowerLabel.setText(QString::number(power));
 	if (mIsOn) {
 		mMotor.setPower(power);
 	}

trikGui/motorLever.h

@@ -72,7 +72,6 @@ class MotorLever : public QWidget
 	QHBoxLayout mLayout;
 	QLabel mNameLabel;
 	QProgressBar mPowerBar;
-	QLabel mPowerLabel;
 	QLabel mOnOffLabel;
 };
 

trikGui/motorsWidget.cpp

@@ -14,15 +14,17 @@
 
 #include "motorsWidget.h"
 
+#include <QtCore/QTimer>
 #include <QtGui/QKeyEvent>
 
 #if QT_VERSION < QT_VERSION_CHECK(5, 0, 0)
 	#include <QtGui/QVBoxLayout>
+	#include <QtGui/QScrollArea>
 #else
 	#include <QtWidgets/QVBoxLayout>
+	#include <QtWidgets/QScrollArea>
 #endif
 
-#include "verticalScrollArea.h"
 #include "motorLever.h"
 
 using namespace trikGui;
@@ -35,8 +37,11 @@ MotorsWidget::MotorsWidget(trikControl::BrickInterface &brick
 	, mPorts(mBrick.motorPorts(type))
 	, mLevers(mPorts.size())
 {
-	const auto scrollArea = new VerticalScrollArea(this);
+	const auto scrollArea = new QScrollArea(this);
 	scrollArea->setFrameStyle(QFrame::NoFrame);
+	scrollArea->setWidgetResizable(true);
+	scrollArea->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+	scrollArea->setAlignment(Qt::AlignHCenter | Qt::AlignVCenter);
 
 	const auto leversWidget = new QWidget(this);
 	const auto innerLayout = new QVBoxLayout(this);
@@ -55,8 +60,11 @@ MotorsWidget::MotorsWidget(trikControl::BrickInterface &brick
 	leversWidget->setLayout(innerLayout);
 
 	outerLayout->addWidget(scrollArea);
+	delete this->layout();
 	this->setLayout(outerLayout);
 	scrollArea->setWidget(leversWidget);
+
+	QTimer::singleShot(0, this, SLOT(fixLeversPosition()));
 }
 
 MotorsWidget::~MotorsWidget()
@@ -102,3 +110,9 @@ void MotorsWidget::keyPressEvent(QKeyEvent *event)
 		}
 	}
 }
+
+void MotorsWidget::fixLeversPosition()
+{
+	focusNextChild();
+	focusPreviousChild();
+}

trikGui/motorsWidget.h

@@ -63,6 +63,11 @@ class MotorsWidget : public TrikGuiDialog
 protected:
 	void keyPressEvent(QKeyEvent *event) override;
 
+private slots:
+	/// Hack to work around odd QScrollArea behavior which incorrectly positions inner widget when there is no need for
+	/// vertical scrollbar.
+	void fixLeversPosition();
+
 private:
 	trikControl::BrickInterface &mBrick;
 	QStringList mPorts;

trikGui/trikGui.pro

@@ -44,7 +44,6 @@ HEADERS += \
 	$$PWD/trikGuiDialog.h \
 	$$PWD/trikGuiMessageBox.h \
 	$$PWD/updateWidget.h \
-	$$PWD/verticalScrollArea.h \
 	$$PWD/wiFiAPWidget.h \
 	$$PWD/wiFiClientWidget.h \
 	$$PWD/wiFiInitWidget.h \
@@ -77,7 +76,6 @@ SOURCES += \
 	$$PWD/trikGuiDialog.cpp \
 	$$PWD/trikGuiMessageBox.cpp \
 	$$PWD/updateWidget.cpp \
-	$$PWD/verticalScrollArea.cpp \
 	$$PWD/wiFiAPWidget.cpp \
 	$$PWD/wiFiClientWidget.cpp \
 	$$PWD/wiFiInitWidget.cpp \