dudong-v2/ui/dialogs/image_preview_dialog.py

"""
Image Preview Dialog

Dialog for displaying enlarged view of images/spectrograms with zoom functionality.
"""

from PyQt5.QtWidgets import QDialog, QVBoxLayout, QLabel, QPushButton, QHBoxLayout, QScrollArea
from PyQt5.QtCore import Qt
from PyQt5.QtGui import QPixmap, QFont


class ImagePreviewDialog(QDialog):
    """
    Dialog for displaying enlarged image previews with zoom functionality.
    
    Features:
    - Enlarged view of spectrograms/images
    - Zoom in/out with buttons or keyboard (+/- or scroll wheel)
    - Click anywhere or press ESC to close
    - Clean, professional appearance
    """
    
    def __init__(self, pixmap: QPixmap, title: str = "Preview", parent=None):
        """
        Initialize the preview dialog.
        
        Args:
            pixmap: QPixmap to display
            title: Dialog title
            parent: Parent widget
        """
        super().__init__(parent)
        self.original_pixmap = pixmap
        self.setWindowTitle(title)
        self.setModal(True)
        self.zoom_level = 1.0
        self.min_zoom = 0.25
        self.max_zoom = 4.0
        self.init_ui()
        
    def init_ui(self):
        """Initialize the dialog UI."""
        layout = QVBoxLayout(self)
        layout.setContentsMargins(0, 0, 0, 0)
        layout.setSpacing(0)
        
        # Header
        header = QLabel(self.windowTitle())
        header.setAlignment(Qt.AlignCenter)
        header.setStyleSheet("""
            QLabel {
                background-color: #2c3e50;
                color: white;
                font-weight: bold;
                font-size: 12px;
                padding: 10px;
            }
        """)
        layout.addWidget(header)
        
        # Scroll area for image with zoom
        scroll_area = QScrollArea()
        scroll_area.setStyleSheet("""
            QScrollArea {
                background-color: #2c3e50;
                border: none;
            }
        """)
        scroll_area.setWidgetResizable(True)
        
        # Image display label
        self.image_label = QLabel()
        self.image_label.setAlignment(Qt.AlignCenter)
        self.image_label.setStyleSheet("""
            QLabel {
                background-color: #2c3e50;
                padding: 20px;
            }
        """)
        
        # Initial scaling to fit dialog (max 1200x800)
        initial_pixmap = self.original_pixmap.scaled(
            1200, 800, Qt.KeepAspectRatio, Qt.SmoothTransformation
        )
        self.image_label.setPixmap(initial_pixmap)
        self.zoom_level = 1.0
        self.current_display_pixmap = initial_pixmap
        
        scroll_area.setWidget(self.image_label)
        layout.addWidget(scroll_area)
        
        # Control buttons and zoom info
        controls_layout = QHBoxLayout()
        controls_layout.setContentsMargins(10, 10, 10, 10)
        controls_layout.setSpacing(10)
        
        # Zoom out button
        zoom_out_button = QPushButton("🔍−  Zoom Out")
        zoom_out_button.setFont(QFont("Arial", 10))
        zoom_out_button.setFixedHeight(35)
        zoom_out_button.setStyleSheet("""
            QPushButton {
                background-color: #34495e;
                color: white;
                border: none;
                font-weight: bold;
                border-radius: 4px;
            }
            QPushButton:hover {
                background-color: #2c3e50;
            }
            QPushButton:pressed {
                background-color: #1a252f;
            }
        """)
        zoom_out_button.clicked.connect(self.zoom_out)
        controls_layout.addWidget(zoom_out_button)
        
        # Zoom level label
        self.zoom_label = QLabel("100%")
        self.zoom_label.setAlignment(Qt.AlignCenter)
        self.zoom_label.setFont(QFont("Arial", 10, QFont.Bold))
        self.zoom_label.setStyleSheet("color: white; min-width: 60px;")
        controls_layout.addWidget(self.zoom_label)
        
        # Zoom in button
        zoom_in_button = QPushButton("Zoom In  🔍+")
        zoom_in_button.setFont(QFont("Arial", 10))
        zoom_in_button.setFixedHeight(35)
        zoom_in_button.setStyleSheet("""
            QPushButton {
                background-color: #34495e;
                color: white;
                border: none;
                font-weight: bold;
                border-radius: 4px;
            }
            QPushButton:hover {
                background-color: #2c3e50;
            }
            QPushButton:pressed {
                background-color: #1a252f;
            }
        """)
        zoom_in_button.clicked.connect(self.zoom_in)
        controls_layout.addWidget(zoom_in_button)
        
        # Reset zoom button
        reset_button = QPushButton("Reset (R)")
        reset_button.setFont(QFont("Arial", 10))
        reset_button.setFixedHeight(35)
        reset_button.setStyleSheet("""
            QPushButton {
                background-color: #7f8c8d;
                color: white;
                border: none;
                font-weight: bold;
                border-radius: 4px;
            }
            QPushButton:hover {
                background-color: #6c7a7d;
            }
            QPushButton:pressed {
                background-color: #5a6667;
            }
        """)
        reset_button.clicked.connect(self.reset_zoom)
        controls_layout.addWidget(reset_button)
        
        # Close button
        close_button = QPushButton("Close (ESC)")
        close_button.setFont(QFont("Arial", 10))
        close_button.setFixedHeight(35)
        close_button.setStyleSheet("""
            QPushButton {
                background-color: #e74c3c;
                color: white;
                border: none;
                font-weight: bold;
                border-radius: 4px;
            }
            QPushButton:hover {
                background-color: #c0392b;
            }
            QPushButton:pressed {
                background-color: #a93226;
            }
        """)
        close_button.clicked.connect(self.accept)
        controls_layout.addWidget(close_button)
        
        layout.addLayout(controls_layout)
        
        # Set dialog size
        self.resize(1280, 900)
        
    def zoom_in(self):
        """Increase zoom level."""
        if self.zoom_level < self.max_zoom:
            self.zoom_level *= 1.25
            if self.zoom_level > self.max_zoom:
                self.zoom_level = self.max_zoom
            self._update_display()
    
    def zoom_out(self):
        """Decrease zoom level."""
        if self.zoom_level > self.min_zoom:
            self.zoom_level /= 1.25
            if self.zoom_level < self.min_zoom:
                self.zoom_level = self.min_zoom
            self._update_display()
    
    def reset_zoom(self):
        """Reset to initial zoom level."""
        self.zoom_level = 1.0
        # Re-scale to fit dialog
        scaled_pixmap = self.original_pixmap.scaled(
            1200, 800, Qt.KeepAspectRatio, Qt.SmoothTransformation
        )
        self.image_label.setPixmap(scaled_pixmap)
        self.current_display_pixmap = scaled_pixmap
        self._update_zoom_label()
    
    def _update_display(self):
        """Update the displayed image based on current zoom level."""
        # Calculate new size based on original pixmap and zoom level
        new_width = int(self.original_pixmap.width() * self.zoom_level)
        new_height = int(self.original_pixmap.height() * self.zoom_level)
        
        # Scale the image
        scaled_pixmap = self.original_pixmap.scaled(
            new_width, new_height, Qt.KeepAspectRatio, Qt.SmoothTransformation
        )
        self.image_label.setPixmap(scaled_pixmap)
        self.current_display_pixmap = scaled_pixmap
        self._update_zoom_label()
    
    def _update_zoom_label(self):
        """Update zoom percentage label."""
        zoom_percentage = int(self.zoom_level * 100)
        self.zoom_label.setText(f"{zoom_percentage}%")
        
    def mousePressEvent(self, event):
        """Close dialog on mouse click outside the scroll area."""
        # Only close if clicking on dialog background, not on scroll area
        if not self.image_label.geometry().contains(self.mapFromGlobal(event.globalPos())):
            self.accept()
        
    def wheelEvent(self, event):
        """Handle mouse wheel for zooming."""
        if event.angleDelta().y() > 0:
            self.zoom_in()
        else:
            self.zoom_out()
        
    def keyPressEvent(self, event):
        """Handle keyboard shortcuts for zooming."""
        if event.key() == Qt.Key_Escape:
            self.accept()
        elif event.key() == Qt.Key_Plus or event.key() == Qt.Key_Equal:
            self.zoom_in()
        elif event.key() == Qt.Key_Minus:
            self.zoom_out()
        elif event.key() == Qt.Key_R:
            self.reset_zoom()
        else:
            super().keyPressEvent(event)