First Commit

Projects/01_UnitConverter/mainwindow.cpp

@@ -0,0 +1,83 @@
+#include "mainwindow.h"
+#include "ui_mainwindow.h"
+#include "conversion.h"
+#include <QClipboard>
+#include <QApplication>
+
+MainWindow::MainWindow(QWidget *parent)
+    : QMainWindow(parent), ui(new Ui::MainWindow)
+{
+    ui->setupUi(this);
+    ui->categoryCombo->addItems({tr("温度"), tr("长度")});
+    connect(ui->categoryCombo, static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged),
+            this, &MainWindow::changeCategory);
+    connect(ui->convertButton, &QPushButton::clicked, this, &MainWindow::convertValue);
+    connect(ui->inputEdit, &QLineEdit::returnPressed, this, &MainWindow::convertValue);
+    connect(ui->inputEdit, &QLineEdit::textChanged, this, &MainWindow::clearResult);
+    connect(ui->fromCombo, static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged),
+            this, &MainWindow::clearResult);
+    connect(ui->toCombo, static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged),
+            this, &MainWindow::clearResult);
+    connect(ui->swapButton, &QPushButton::clicked, this, [this] {
+        const int previousFrom = ui->fromCombo->currentIndex();
+        ui->fromCombo->setCurrentIndex(ui->toCombo->currentIndex());
+        ui->toCombo->setCurrentIndex(previousFrom);
+        ui->inputEdit->setFocus();
+    });
+    connect(ui->clearButton, &QPushButton::clicked, this, [this] {
+        ui->inputEdit->clear();
+        clearResult();
+        ui->inputEdit->setFocus();
+    });
+    connect(ui->copyButton, &QPushButton::clicked, this, [this] {
+        QApplication::clipboard()->setText(ui->resultEdit->text());
+        ui->statusLabel->setText(tr("结果已复制。"));
+    });
+    changeCategory();
+    ui->inputEdit->setText(QStringLiteral("25"));
+}
+
+MainWindow::~MainWindow() { delete ui; }
+
+void MainWindow::changeCategory()
+{
+    const auto category = ui->categoryCombo->currentIndex() == 0
+        ? Conversion::Category::Temperature : Conversion::Category::Length;
+    const QStringList names = Conversion::units(category);
+    ui->fromCombo->clear();
+    ui->toCombo->clear();
+    ui->fromCombo->addItems(names);
+    ui->toCombo->addItems(names);
+    ui->fromCombo->setCurrentIndex(category == Conversion::Category::Length ? 2 : 0);
+    ui->toCombo->setCurrentIndex(1);
+    clearResult();
+}
+
+void MainWindow::clearResult()
+{
+    ui->resultEdit->clear();
+    ui->formulaLabel->setText(tr("选择单位并输入数值，点击“换算”查看计算过程。"));
+    ui->statusLabel->clear();
+    ui->copyButton->setEnabled(false);
+}
+
+void MainWindow::convertValue()
+{
+    const auto category = ui->categoryCombo->currentIndex() == 0
+        ? Conversion::Category::Temperature : Conversion::Category::Length;
+    const auto result = Conversion::convert(ui->inputEdit->text(), category,
+                                            ui->fromCombo->currentIndex(),
+                                            ui->toCombo->currentIndex());
+    if (!result.ok) {
+        clearResult();
+        ui->statusLabel->setText(result.error);
+        ui->inputEdit->setFocus();
+        return;
+    }
+    ui->resultEdit->setText(QStringLiteral("%1 %2")
+        .arg(result.value, 0, 'g', 12).arg(ui->toCombo->currentText()));
+    ui->formulaLabel->setText(result.explanation);
+    ui->statusLabel->setText(tr("换算完成。结果最多显示 12 位有效数字。"));
+    ui->copyButton->setEnabled(true);
+}
+