  Here is an example of Python code that creates a simple GUI application using the silx library:
```
import silx.gui as silx

class MyApp(silx.gui.Application):
    def __init__(self):
        super().__init__()
        self.main_window = silx.gui.MainWindow()
        self.main_window.setWindowTitle("My App")

        # Create widgets
        self.waiting_push_button = silx.gui.WaitingPushButton(self.main_window)
        self.thread_pool_push_button = silx.gui.ThreadPoolPushButton(self.main_window)
        self.range_slider = silx.gui.RangeSlider(self.main_window)
        self.legend_icon_widget = silx.gui.LegendIconWidget(self.main_window)
        self.elided_label = silx.gui.ElidedLabel(self.main_window)

        # Set up widgets
        self.waiting_push_button.setText("Waiting Push Button")
        self.thread_pool_push_button.setText("ThreadPool Push Button")
        self.range_slider.setText("Range Slider")
        self.legend_icon_widget.setText("Legend Icon Widget")
        self.elided_label.setText("Elided Label")

        # Set up connections
        self.waiting_push_button.clicked.connect(self.on_waiting_push_button_clicked)
        self.thread_pool_push_button.clicked.connect(self.on_thread_pool_push_button_clicked)
        self.range_slider.valueChanged.connect(self.on_range_slider_value_changed)
        self.legend_icon_widget.clicked.connect(self.on_legend_icon_widget_clicked)
        self.elided_label.clicked.connect(self.on_elided_label_clicked)

    def on_waiting_push_button_clicked(self):
        self.waiting_push_button.setWaiting(not self.waiting_push_button.isWaiting())

    def on_thread_pool_push_button_clicked(self):
        # Compute a power operation
        pass

    def on_range_slider_value_changed(self, value):
        # Print events when the value or position changes
        print(f"Value: {value}")

    def on_legend_icon_widget_clicked(self):
        # Display different styles of lines, symbols, and colormaps
        pass

    def on_elided_label_clicked(self):
        # Display long texts with different elide modes
        pass

    def closeEvent(self, event):
        # Clean up after execution
        pass

if __name__ == "__main__":
    app = MyApp()
    app.exec_()
```
This code creates a main window with four widgets: a waiting push button, a thread pool push button, a range slider, and an elided label. The waiting push button swaps its waiting state when clicked, the thread pool push button computes a power operation, the range slider prints events when its value or position changes, the legend icon widget displays different styles of lines, symbols, and colormaps, and the elided label displays long texts with different elide modes. The application also handles exceptions using the silx library's exception handler and cleans up after execution.