initial commit

client/gui/dialogs/ImageCropDialog.cpp

@@ -0,0 +1,209 @@
+#include "dialogs/ImageCropDialog.h"
+
+#include <QBoxLayout>
+#include <QDialogButtonBox>
+#include <QLabel>
+#include <QMouseEvent>
+#include <QPainter>
+#include <QPushButton>
+#include <QtMath>
+
+class ImageCropDialog::CropView final : public QWidget {
+public:
+    explicit CropView(QWidget* parent = nullptr)
+        : QWidget(parent) {
+        setMouseTracking(true);
+        setMinimumSize(480, 320);
+    }
+
+    void setImage(const QImage& img) {
+        m_image = img;
+        m_selection = {};
+        updateGeometry();
+        update();
+    }
+
+    bool hasSelection() const { return !m_selection.isNull() && m_selection.width() > 0 && m_selection.height() > 0; }
+
+    QRect selectionInImagePixels() const {
+        if (m_image.isNull() || !hasSelection()) {
+            return {};
+        }
+        const auto map = viewToImageTransform();
+        // selection 是 view 坐标；映射到 image 像素坐标
+        const QRectF selF = QRectF(m_selection).normalized();
+        bool invertible = false;
+        const QTransform inv = map.inverted(&invertible);
+        if (!invertible) {
+            return {};
+        }
+
+        const QPointF topLeftImg = inv.map(selF.topLeft());
+        const QPointF bottomRightImg = inv.map(selF.bottomRight());
+
+        // 使用 floor/ceil，避免因为取整导致宽高变 0
+        const int left = qFloor(std::min(topLeftImg.x(), bottomRightImg.x()));
+        const int top = qFloor(std::min(topLeftImg.y(), bottomRightImg.y()));
+        const int right = qCeil(std::max(topLeftImg.x(), bottomRightImg.x()));
+        const int bottom = qCeil(std::max(topLeftImg.y(), bottomRightImg.y()));
+
+        QRect r(QPoint(left, top), QPoint(right, bottom));
+        r = r.normalized().intersected(QRect(0, 0, m_image.width(), m_image.height()));
+        return r;
+    }
+
+    void resetSelection() {
+        m_selection = {};
+        update();
+    }
+
+protected:
+    void paintEvent(QPaintEvent*) override {
+        QPainter p(this);
+        p.fillRect(rect(), palette().window());
+
+        if (m_image.isNull()) {
+            p.setPen(palette().text().color());
+            p.drawText(rect(), Qt::AlignCenter, QStringLiteral("无法加载图片"));
+            return;
+        }
+
+        const auto map = viewToImageTransform();
+        p.setRenderHint(QPainter::SmoothPixmapTransform, true);
+        p.setTransform(map);
+        p.drawImage(QPoint(0, 0), m_image);
+        p.resetTransform();
+
+        if (hasSelection()) {
+            // 避免 CompositionMode_Clear 在某些平台/样式下表现异常：
+            // 用“围绕选区画四块遮罩”的方式实现高亮裁剪区域。
+            const QRect sel = m_selection.normalized().intersected(rect());
+            const QColor shade(0, 0, 0, 120);
+
+            // 上
+            p.fillRect(QRect(0, 0, width(), sel.top()), shade);
+            // 下
+            p.fillRect(QRect(0, sel.bottom(), width(), height() - sel.bottom()), shade);
+            // 左
+            p.fillRect(QRect(0, sel.top(), sel.left(), sel.height()), shade);
+            // 右
+            p.fillRect(QRect(sel.right(), sel.top(), width() - sel.right(), sel.height()), shade);
+
+            p.setPen(QPen(QColor(255, 255, 255, 220), 2));
+            p.drawRect(sel);
+        }
+    }
+
+    void mousePressEvent(QMouseEvent* e) override {
+        if (m_image.isNull() || e->button() != Qt::LeftButton) {
+            return;
+        }
+        m_dragging = true;
+        m_anchor = e->position().toPoint();
+        m_selection = QRect(m_anchor, m_anchor);
+        update();
+    }
+
+    void mouseMoveEvent(QMouseEvent* e) override {
+        if (!m_dragging) {
+            return;
+        }
+        const QPoint cur = e->position().toPoint();
+        m_selection = QRect(m_anchor, cur).normalized();
+        update();
+    }
+
+    void mouseReleaseEvent(QMouseEvent* e) override {
+        if (e->button() != Qt::LeftButton) {
+            return;
+        }
+        m_dragging = false;
+        update();
+    }
+
+private:
+    QTransform viewToImageTransform() const {
+        // 让图片按比例 fit 到 view 中居中显示
+        const QSizeF viewSize = size();
+        const QSizeF imgSize = m_image.size();
+        const qreal sx = viewSize.width() / imgSize.width();
+        const qreal sy = viewSize.height() / imgSize.height();
+        const qreal s = std::min(sx, sy);
+
+        const qreal drawW = imgSize.width() * s;
+        const qreal drawH = imgSize.height() * s;
+        const qreal offsetX = (viewSize.width() - drawW) / 2.0;
+        const qreal offsetY = (viewSize.height() - drawH) / 2.0;
+
+        QTransform t;
+        t.translate(offsetX, offsetY);
+        t.scale(s, s);
+        return t;
+    }
+
+private:
+    QImage m_image;
+    bool m_dragging = false;
+    QPoint m_anchor;
+    QRect m_selection;
+};
+
+ImageCropDialog::ImageCropDialog(const QString& imagePath, QWidget* parent)
+    : QDialog(parent),
+      m_imagePath(imagePath) {
+    setWindowTitle(QStringLiteral("裁剪图片"));
+    setModal(true);
+    resize(900, 600);
+    loadImageOrClose();
+    rebuildUi();
+}
+
+void ImageCropDialog::loadImageOrClose() {
+    m_image = QImage(m_imagePath);
+    if (m_image.isNull()) {
+        reject();
+    }
+}
+
+void ImageCropDialog::rebuildUi() {
+    auto* root = new QVBoxLayout(this);
+
+    auto* hint = new QLabel(QStringLiteral("拖拽选择裁剪区域（不选则使用整张图）。"), this);
+    root->addWidget(hint);
+
+    m_view = new CropView(this);
+    m_view->setImage(m_image);
+    root->addWidget(m_view, 1);
+
+    auto* buttons = new QDialogButtonBox(QDialogButtonBox::Ok | QDialogButtonBox::Cancel, this);
+    m_okButton = buttons->button(QDialogButtonBox::Ok);
+    auto* resetBtn = new QPushButton(QStringLiteral("重置选择"), this);
+    buttons->addButton(resetBtn, QDialogButtonBox::ActionRole);
+
+    connect(resetBtn, &QPushButton::clicked, this, &ImageCropDialog::onReset);
+    connect(buttons, &QDialogButtonBox::accepted, this, &ImageCropDialog::onOk);
+    connect(buttons, &QDialogButtonBox::rejected, this, &ImageCropDialog::reject);
+    root->addWidget(buttons);
+}
+
+bool ImageCropDialog::hasValidSelection() const {
+    return m_view && m_view->hasSelection();
+}
+
+QRect ImageCropDialog::selectedRectInImagePixels() const {
+    if (!m_view) {
+        return {};
+    }
+    return m_view->selectionInImagePixels();
+}
+
+void ImageCropDialog::onReset() {
+    if (m_view) {
+        m_view->resetSelection();
+    }
+}
+
+void ImageCropDialog::onOk() {
+    accept();
+}
+