slider checkpoint

src/MainWindow.cpp

@@ -0,0 +1,88 @@
+
+#include "MainWindow.h"
+#include "ui_MainWindow.h"
+
+MainWindow::MainWindow(QWidget *parent)
+    : QMainWindow(parent),
+      ui(new Ui::MainWindow)
+{
+    ui->setupUi(this);
+
+    // Initialize UI
+    updateCounterLabel();
+
+    // Connect buttons to slots
+    connect(ui->buttonIncrement, &QPushButton::clicked, this, &MainWindow::onIncrementClicked);
+    connect(ui->buttonReset, &QPushButton::clicked, this, &MainWindow::onResetClicked);
+
+    // slider business
+    connect(ui->slider,     &QSlider::valueChanged,      this, &MainWindow::onSliderValueChanged);
+    connect(ui->inputMin,   &QLineEdit::editingFinished, this, &MainWindow::onMinChanged);
+    connect(ui->inputMax,   &QLineEdit::editingFinished, this, &MainWindow::onMaxChanged);
+    connect(ui->inputStep,  &QLineEdit::editingFinished, this, &MainWindow::onStepChanged);
+    connect(ui->inputValue, &QLineEdit::editingFinished, this, &MainWindow::onValueChanged);
+
+}
+
+MainWindow::~MainWindow() {
+    delete ui;
+}
+
+void MainWindow::onIncrementClicked() {
+    counter_++;
+    updateCounterLabel();
+}
+
+void MainWindow::onResetClicked() {
+    counter_ = 0;
+    updateCounterLabel();
+}
+
+void MainWindow::updateCounterLabel() {
+    ui->labelCounter->setText(QString::number(counter_));
+}
+
+// allows only numbers to be set
+void MainWindow::onSliderValueChanged(int value) { 
+    QSignalBlocker blocker(ui->inputValue);
+    ui->inputValue->setText(QString::number(value));
+}
+
+// allows only values within the min, max to be set by the text field
+void MainWindow::onValueChanged() {
+    bool ok = false;
+    int value = ui->inputValue->text().toInt(&ok);
+    if(!ok) return;
+
+    value = qBound(ui->slider->minimum(), value, ui->slider->maximum());
+    ui->slider->setValue(value);
+}
+
+void MainWindow::applySliderRange() {
+    bool minOk, maxOk;
+    int min = ui->inputMin->text().toInt(&minOk);
+    int max = ui->inputMax->text().toInt(&maxOk);
+    if(!minOk || !maxOk || min > max) return;
+    
+    ui->slider->setRange(min, max);
+
+    syncValueToUi(ui->slider->value());
+}
+
+void MainWindow::applySliderStep() {
+    bool ok;
+    int step = ui->inputStep->text().toInt(&ok);
+    if(!ok || step <= 0) return;
+    
+    ui->slider->setSingleStep(step);
+    ui->slider->setPageStep(step);
+}
+
+void MainWindow::syncValueToUi(int value) {
+    QSignalBlocker block1(ui->slider);
+    QSignalBlocker block2(ui->inputValue);
+
+    value = qBound(ui->slider->minimum(), value, ui->slider->maximum());
+    ui->slider->setValue(value);
+    ui->inputValue->setText(QString::number(value));
+}