First Commit

Projects/02_ClassroomTimer/mainwindow.cpp

@@ -0,0 +1,91 @@
+#include "mainwindow.h"
+#include "ui_mainwindow.h"
+#include <QApplication>
+#include <QShortcut>
+
+MainWindow::MainWindow(QWidget *parent)
+    : QMainWindow(parent), ui(new Ui::MainWindow)
+{
+    ui->setupUi(this);
+    m_clock.start();
+    m_refreshTimer.setInterval(100);
+    connect(&m_refreshTimer, &QTimer::timeout, this, &MainWindow::refreshDisplay);
+    for (QSpinBox *spin : {ui->hoursSpin, ui->minutesSpin, ui->secondsSpin})
+        connect(spin, static_cast<void (QSpinBox::*)(int)>(&QSpinBox::valueChanged),
+                this, &MainWindow::durationChanged);
+    connect(ui->startButton, &QPushButton::clicked, this, [this] {
+        m_countdown.start(m_clock.elapsed());
+        refreshDisplay();
+    });
+    connect(ui->pauseButton, &QPushButton::clicked, this, [this] {
+        const auto previousState = m_countdown.state();
+        m_countdown.pause(m_clock.elapsed());
+        if (previousState == Countdown::State::Running
+                && m_countdown.state() == Countdown::State::Finished
+                && ui->soundCheck->isChecked())
+            QApplication::beep();
+        refreshDisplay();
+    });
+    connect(ui->resetButton, &QPushButton::clicked, this, [this] {
+        m_countdown.reset();
+        refreshDisplay();
+    });
+    connect(ui->fullscreenButton, &QPushButton::clicked, this, [this] {
+        if (isFullScreen()) showNormal(); else showFullScreen();
+        ui->fullscreenButton->setText(isFullScreen() ? tr("退出全屏") : tr("全屏显示"));
+    });
+    auto *escape = new QShortcut(QKeySequence(Qt::Key_Escape), this);
+    connect(escape, &QShortcut::activated, this, [this] {
+        if (isFullScreen()) {
+            showNormal();
+            ui->fullscreenButton->setText(tr("全屏显示"));
+        }
+    });
+    durationChanged();
+}
+
+MainWindow::~MainWindow() { delete ui; }
+
+void MainWindow::durationChanged()
+{
+    const qint64 seconds = ui->hoursSpin->value() * 3600
+        + ui->minutesSpin->value() * 60 + ui->secondsSpin->value();
+    m_countdown.setDuration(seconds * 1000);
+    refreshDisplay();
+}
+
+void MainWindow::refreshDisplay()
+{
+    const qint64 now = m_clock.elapsed();
+    const auto previousState = m_countdown.state();
+    m_countdown.update(now);
+    const auto state = m_countdown.state();
+    const bool running = state == Countdown::State::Running;
+    const bool paused = state == Countdown::State::Paused;
+    if (running && !m_refreshTimer.isActive()) m_refreshTimer.start();
+    if (!running) m_refreshTimer.stop();
+    const qint64 remaining = m_countdown.remaining(now);
+    // 向上取整：还剩 1 毫秒时显示 1 秒，真正到时才显示零。
+    const qint64 seconds = (remaining + 999) / 1000;
+    ui->timeLabel->setText(QStringLiteral("%1:%2:%3")
+        .arg(seconds / 3600, 2, 10, QLatin1Char('0'))
+        .arg((seconds / 60) % 60, 2, 10, QLatin1Char('0'))
+        .arg(seconds % 60, 2, 10, QLatin1Char('0')));
+    ui->progressBar->setValue(m_countdown.duration() == 0 ? 0
+        : static_cast<int>(remaining * 1000 / m_countdown.duration()));
+    ui->durationGroup->setEnabled(!running && !paused);
+    ui->startButton->setEnabled(!running && m_countdown.duration() > 0);
+    ui->pauseButton->setEnabled(running);
+    ui->startButton->setText(paused ? tr("继续") :
+        state == Countdown::State::Finished ? tr("重新开始") : tr("开始"));
+    if (running) ui->statusLabel->setText(tr("正在计时"));
+    else if (paused) ui->statusLabel->setText(tr("已暂停 · 点击“继续”接着计时"));
+    else if (state == Countdown::State::Finished)
+        ui->statusLabel->setText(tr("时间到！本轮计时已结束。"));
+    else ui->statusLabel->setText(m_countdown.duration() > 0
+        ? tr("准备就绪 · 点击“开始”") : tr("请先设置大于 0 的时长。"));
+    if (previousState == Countdown::State::Running && state == Countdown::State::Finished
+            && ui->soundCheck->isChecked())
+        QApplication::beep();
+}
+