Squashed commit of the following:

commit bf69c55
Author: Gabriel Simas <autorgabrielsimas@gmail.com>
Date:   Sun Feb 2 15:54:07 2025 -0300

    Feature/challenge resolved (#3)

    * Challenge OK

    * Atualizando o README com um novo vídeo

    ---------

    Co-authored-by: Luís Gabriel Nascimento Simas <luis.gabriel_thera@prestador.globo>

commit 5af4965
Author: Gabriel Simas <autorgabrielsimas@gmail.com>
Date:   Fri Jan 31 12:11:34 2025 -0300

    First Commit - README.md (#1)

    Co-authored-by: Luís Gabriel Nascimento Simas <luis.gabriel_thera@prestador.globo>

# Conflicts:
#	README.md

Author: Luís Gabriel Nascimento Simas

.gitignore

@@ -135,6 +135,7 @@ venv/
 ENV/
 env.bak/
 venv.bak/
+virtualenv/
 
 # Spyder project settings
 .spyderproject

README.md

@@ -5,8 +5,12 @@
 ## Project Description
 
 In this project, we will build a simple image gallery viewer where users can browse through images stored in a folder. The app will allow the user to select a folder from their computer and display the images of that folder:
-
-![Alt Text](image.gif)
+<p align="center">
+  <img src="result.gif" />
+</p>
+<p align="center">
+  <img src="result_2.gif" />
+</p>
 
 This project is useful for building a GUI application using one of the best GUI libraries such as PyQt6, and it introduces users to managing file systems, working with images, and handling GUI events.
 

main.py

@@ -0,0 +1,14 @@
+import sys
+from src.main_window import MainWindow
+from PyQt6.QtWidgets import QApplication
+
+
+def main():
+    app = QApplication(sys.argv)
+    window = MainWindow()
+    window.show()
+    sys.exit(app.exec())
+
+
+if __name__ == "__main__":
+    main()

result.gif

@@ -0,0 +1,76 @@
+import os
+from PyQt6.QtCore import Qt
+from src.image_model import ImageModel
+from PyQt6.QtWidgets import (
+    QLabel,
+    QWidget,
+    QPushButton,
+    QHBoxLayout,
+    QVBoxLayout,
+)
+from PyQt6.QtGui import QPixmap
+
+
+class ImageGalleryWidget(QWidget):
+    """
+    The central widget displaying the current image,
+    with Previous/Next buttons. Connects to an ImageModel
+    to load images and update the display.
+    """
+
+    def __init__(self, model: ImageModel):
+        super().__init__()
+        self._model = model
+        # Widgets
+        self._image_label = QLabel("No image loaded.")
+        self._image_label.setAlignment(Qt.AlignmentFlag.AlignCenter)
+
+        self._prev_button = QPushButton("Previous")
+        self._next_button = QPushButton("Next")
+        # Layouts
+        button_layout = QHBoxLayout()
+        button_layout.addWidget(self._prev_button)
+        button_layout.addWidget(self._next_button)
+
+        main_layout = QVBoxLayout()
+        main_layout.addWidget(self._image_label, stretch=1)
+        main_layout.addLayout(button_layout)
+
+        self.setLayout(main_layout)
+
+        # Button Signals
+        self._prev_button.clicked.connect(self.show_previous_image)
+        self._next_button.clicked.connect(self.show_next_image)
+
+    def load_current_image(self):
+        """
+        Loads the current image from the model, if any.
+        """
+        path = self._model.get_current_image_path()
+        if path and os.path.isfile(path):
+            pixmap = QPixmap(path)
+
+            # Optionally scale to label
+            scale_pixmap = pixmap.scaled(
+                self._image_label.size(),
+                Qt.AspectRatioMode.KeepAspectRatio,
+                Qt.TransformationMode.SmoothTransformation,
+            )
+            self._image_label.setPixmap(scale_pixmap)
+        else:
+            self._image_label.setText("No image loaded.")
+
+    def show_previous_image(self):
+        self._model.previous_image()
+        self.load_current_image()
+
+    def show_next_image(self):
+        self._model.next_image()
+        self.load_current_image()
+
+    def resizeEvent(self, event):
+        """
+        Called when the widget is resized (so we can re-scale the image).
+        """
+        super().resizeEvent(event)
+        self.load_current_image()

result_2.gif

@@ -0,0 +1,48 @@
+from src.thumbnails_list_widget import ThumbnailListWidget
+
+
+class ImageModel:
+    """
+    Holds the list of image paths, and the current index.
+    Manages navigation logic for next/previous images.
+    """
+
+    def __init__(self):
+        self._image_paths = []
+        self._current_index = -1
+        self._thumbnails_list = None
+
+    def set_images(
+        self,
+        image_paths: list[str],
+        thumbnails_list: ThumbnailListWidget,
+    ):
+        self._image_paths = image_paths
+        self._current_index = 0 if image_paths else -1
+        self._thumbnails_list = thumbnails_list
+
+    def get_current_image_path(self):
+        if 0 <= self._current_index < len(self._image_paths):
+            return self._image_paths[self._current_index]
+        return None
+
+    def next_image(self):
+        if 0 <= self._current_index < len(self._image_paths) - 1:
+            self._current_index += 1
+            if self._thumbnails_list:
+                self._thumbnails_list.select_index(self._current_index)
+
+    def previous_image(self):
+        """
+        Move to the previous image, if possible.
+        """
+        if self._current_index > 0:
+            self._current_index -= 1
+            if self._thumbnails_list:
+                self._thumbnails_list.select_index(self._current_index)
+
+    def jump_to_index(self, index):
+        if 0 <= index < len(self._image_paths):
+            self._current_index = index
+            if self._thumbnails_list:
+                self._thumbnails_list.select_index(self._current_index)

src/image_gallery_widget.py

@@ -0,0 +1,156 @@
+import os
+from PyQt6.QtWidgets import (
+    QMenu,
+    QWidget,
+    QMenuBar,
+    QMainWindow,
+    QHBoxLayout,
+    QFileDialog,
+    QMessageBox,
+)
+
+from PyQt6.QtCore import QTimer, Qt
+from src.image_model import ImageModel
+from PyQt6.QtGui import QKeySequence, QAction
+from src.image_gallery_widget import ImageGalleryWidget
+from src.thumbnails_list_widget import ThumbnailListWidget
+
+
+class MainWindow(QMainWindow):
+    """
+    Combines the ImageGalleryWidget (center),
+    the ThumbnailsListWidget (left), and a member for
+    opening folders and starting/stopping a slideshow
+    """
+
+    def __init__(self):
+        super().__init__()
+        self.setWindowTitle("Customizable Image Gallery")
+        self.resize(1200, 800)
+
+        # Model
+        self._model: ImageModel = ImageModel()        
+
+        # Widgets
+        self._image_gallery_widget = ImageGalleryWidget(self._model)
+        self._thumbnails_list = ThumbnailListWidget(self.on_thumbnails_selected)
+        self._model.set_images([], self._thumbnails_list)
+        # Timer for Slideshow
+        self._slideshow_timer = QTimer()
+        self._slideshow_timer.setInterval(2000)  # 2 seconds per image
+        self._slideshow_timer.timeout.connect(self.handle_slideshow_step)
+        self._slideshow_running = True
+
+        # Layout
+        central_widget = QWidget()
+        main_layout = QHBoxLayout()
+        main_layout.addWidget(self._thumbnails_list, stretch=1)
+        main_layout.addWidget(self._image_gallery_widget, stretch=3)
+        central_widget.setLayout(main_layout)
+        self.setCentralWidget(central_widget)
+
+        # Menubar
+        menubar = self.menuBar() if self.menuBar() else QMenuBar(self)
+        file_menu = menubar.addMenu("File")
+        slideshow_menu = menubar.addMenu("Slideshow")
+
+        open_folder_action = QAction("Open Folder", self)
+        open_folder_action.triggered.connect(self.open_folder)
+        file_menu.addAction(open_folder_action)
+
+        start_slideshow_action = QAction("Start Slideshow", self)
+        start_slideshow_action.triggered.connect(self.start_slideshow)
+        slideshow_menu.addAction(start_slideshow_action)
+
+        stop_slideshow_action = QAction("Stop Slideshow", self)
+        stop_slideshow_action.triggered.connect(self.stop_slideshow)
+        slideshow_menu.addAction(stop_slideshow_action)
+
+        # Keyboard shortcut (Left/Right arrow keys)
+        prev_action = QAction("Previous", self)
+        prev_action.setShortcut(QKeySequence(Qt.Key.Key_Left))
+        prev_action.triggered.connect(self.show_previous_image)
+        self.addAction(prev_action)
+
+        next_action = QAction("Next", self)
+        next_action.setShortcut(QKeySequence(Qt.Key.Key_Right))
+        next_action.triggered.connect(self.show_next_image)
+        self.addAction(next_action)
+
+    def open_folder(self):
+        """
+        Opens a folder dialog and loads images into the model
+        """
+        folder_path = QFileDialog.getExistingDirectory(
+            self,
+            "Select Folder",
+        )
+        if folder_path:
+            valid_extensions = {
+                ".png",
+                ".jpg",
+                ".jpeg",
+                ".bmp",
+                ".gif",
+            }
+            image_paths = [
+                os.path.join(folder_path, f)
+                for f in os.listdir(folder_path)
+                if os.path.splitext(f.lower())[1] in valid_extensions
+            ]
+            image_paths.sort()
+
+            if not image_paths:
+                QMessageBox.warning(self, "Warning", "No images found in this folder")
+                return
+
+            self._model.set_images(image_paths, self._thumbnails_list)
+
+            # Update UI
+            self._image_gallery_widget.load_current_image()
+            self._thumbnails_list.populate(image_paths)
+            self._thumbnails_list.select_index(self._model._current_index)
+
+    def start_slideshow(self):
+        if self._model._image_paths:
+            self._slideshow_timer.start()
+            self._slideshow_running = True
+
+    def stop_slideshow(self):
+        self._slideshow_timer.stop()
+        self._slideshow_running = False
+
+    def handle_slideshow_step(self):
+        """
+        Move to the next image automatically. If we reach the end, wrap around.
+        """
+
+        if not self._model._image_paths:
+            return
+
+        if self._model._current_index >= len(self._model._image_paths) - 1:
+            # Wrap to First
+            self._model._current_index = 0
+        else:
+            self._model.next_image()
+
+        self.update_display()
+
+    def on_thumbnails_selected(self, index):
+        """
+        Called when user selects a thumbnail in the list.
+        """
+        self._model.jump_to_index(index)
+        self.update_display()
+
+    def show_previous_image(self):
+        self._model.previous_image()
+        self.update_display()
+
+    def show_next_image(self):
+        self._model.next_image()
+        self.update_display()
+
+    def update_display(self):
+        self._image_gallery_widget.load_current_image()
+        self._thumbnails_list.select_index(self._model._current_index)

src/image_model.py

@@ -0,0 +1,50 @@
+import os
+from PyQt6.QtCore import QSize
+from PyQt6.QtWidgets import QListWidget, QListWidgetItem
+
+
+class ThumbnailListWidget(QListWidget):
+    """
+    Displays a list of image filenames (or actual thumbnails) on the side.
+    When an item is selected, it calls a callback to let the main app
+    switch to that image
+    """
+
+    def __init__(self, on_item_selected=None):
+        super().__init__()
+        self._on_item_selected = on_item_selected
+        self.setIconSize(QSize(60, 60))  # Adjust thumbnail icon size as needed
+
+        # Connect the selection signal
+        self.itemSelectionChanged.connect(self.handle_selection_changed)
+
+    def populate(self, image_paths):
+        """
+        Clears the list and re-populates with given image paths.
+        Here, we add items with either icons or text.
+        """
+        self.clear()
+        for path in image_paths:
+            item = QListWidgetItem(os.path.basename(path))
+            # If you wanna to show a small thumbnail icon:
+            # pixmap = QPixmax(path)
+            # icon = QIcon(
+            # pixmap.scaled(60, 60, Qt.AspectRatioMode.KeepAspectRatio)
+            # )
+            # item.setIcon(icon)
+            self.addItem(item)
+
+    def handle_selection_changed(self):
+        # Use currentIndex() to get the selected item
+        selected_item = self.currentIndex()
+        if selected_item.isValid():  # Check if the item is selected
+            selected_index = selected_item.row()  # Get the index of the selected item
+            if self._on_item_selected:
+                self._on_item_selected(selected_index)
+
+    def select_index(self, index):
+        """
+        Programmatically select an index in the list.
+        """
+        if 0 <= index < self.count():
+            self.setCurrentRow(index)