examples: Clean up imports

Makes things consistent for the reader:
- Use prelude from gtk as it re-exports glib's prelude
- Stop using imports for stuff that is used only once. It doesn't make the code more readable
- Sort & organize imports, this is done using a rustfmt nightly feature & took that opportunity
to also use it for cleaning up the comments

Author: bilelmoussaoui

examples/basics/main.rs

@@ -1,5 +1,4 @@
-use gtk::glib;
-use gtk::prelude::*;
+use gtk::{glib, prelude::*};
 
 fn main() -> glib::ExitCode {
     let application = gtk::Application::builder()

examples/builder_pattern/main.rs

@@ -1,30 +1,28 @@
-use gtk::prelude::*;
-use gtk::{glib, Align, Application, ApplicationWindow, Button};
+use gtk::{glib, prelude::*};
 
 fn main() -> glib::ExitCode {
-    let application = Application::new(
-        Some("com.github.gtk-rs.examples.builder_pattern"),
-        Default::default(),
-    );
+    let application = gtk::Application::builder()
+        .application_id("com.github.gtk-rs.examples.builder_pattern")
+        .build();
     application.connect_activate(build_ui);
     application.run()
 }
 
-fn build_ui(application: &Application) {
-    let window = ApplicationWindow::builder()
+fn build_ui(application: &gtk::Application) {
+    let window = gtk::ApplicationWindow::builder()
         .application(application)
         .title("First GTK Program")
         .default_width(350)
         .default_height(70)
         .build();
 
-    let button = Button::builder()
+    let button = gtk::Button::builder()
         .margin_top(10)
         .margin_bottom(10)
         .margin_start(10)
         .margin_end(10)
-        .halign(Align::Center)
-        .valign(Align::Center)
+        .halign(gtk::Align::Center)
+        .valign(gtk::Align::Center)
         .label("Click Me!")
         .build();
 

examples/clipboard/main.rs

@@ -1,6 +1,8 @@
-use glib::clone;
-use gtk::prelude::*;
-use gtk::{gdk, gio, glib};
+use gtk::{
+    gdk, gio,
+    glib::{self, clone},
+    prelude::*,
+};
 
 fn main() -> glib::ExitCode {
     let application = gtk::Application::builder()

examples/clock/main.rs

@@ -1,30 +1,30 @@
 use chrono::Local;
-use gtk::glib;
-use gtk::prelude::*;
-use gtk::{Application, ApplicationWindow, Label};
+use gtk::{glib, prelude::*};
 
 fn main() -> glib::ExitCode {
-    let application =
-        Application::new(Some("com.github.gtk-rs.examples.clock"), Default::default());
+    let application = gtk::Application::builder()
+        .application_id("com.github.gtk-rs.examples.clock")
+        .build();
     application.connect_activate(build_ui);
     application.run()
 }
 
-fn build_ui(application: &Application) {
-    let window = ApplicationWindow::new(application);
+fn build_ui(application: &gtk::Application) {
+    let window = gtk::ApplicationWindow::new(application);
 
     window.set_title(Some("Clock Example"));
     window.set_default_size(260, 40);
 
     let time = current_time();
-    let label = Label::new(None);
+    let label = gtk::Label::default();
     label.set_text(&time);
 
     window.set_child(Some(&label));
 
     window.present();
 
-    // we are using a closure to capture the label (else we could also use a normal function)
+    // we are using a closure to capture the label (else we could also use a normal
+    // function)
     let tick = move || {
         let time = current_time();
         label.set_text(&time);

examples/column_view_datagrid/grid_cell/imp.rs

@@ -1,5 +1,4 @@
-use gtk::glib;
-use gtk::subclass::prelude::*;
+use gtk::{glib, subclass::prelude::*};
 
 #[derive(Debug, Default, gtk::CompositeTemplate)]
 #[template(file = "grid_cell.ui")]
@@ -18,8 +17,9 @@ impl ObjectSubclass for GridCell {
     type ParentType = gtk::Widget;
 
     fn class_init(klass: &mut Self::Class) {
-        // When inheriting from GtkWidget directly, you have to either override the size_allocate/measure
-        // functions of WidgetImpl trait or use a layout manager which provides those functions for your widgets like below.
+        // When inheriting from GtkWidget directly, you have to either override the
+        // size_allocate/measure functions of WidgetImpl trait or use a layout
+        // manager which provides those functions for your widgets like below.
         klass.set_layout_manager_type::<gtk::BinLayout>();
         klass.bind_template();
     }

examples/column_view_datagrid/grid_cell/mod.rs

@@ -1,6 +1,5 @@
 mod imp;
-use gtk::glib;
-use gtk::subclass::prelude::*;
+use gtk::{glib, subclass::prelude::*};
 
 glib::wrapper! {
     pub struct GridCell(ObjectSubclass<imp::GridCell>)

examples/column_view_datagrid/main.rs

@@ -1,10 +1,12 @@
 mod grid_cell;
 
-use crate::grid_cell::Entry;
-use crate::grid_cell::GridCell;
-use gtk::glib::BoxedAnyObject;
-use gtk::prelude::*;
-use gtk::{gio, glib};
+use gtk::{
+    gio,
+    glib::{self, BoxedAnyObject},
+    prelude::*,
+};
+
+use crate::grid_cell::{Entry, GridCell};
 
 struct Row {
     col1: String,

examples/composite_template/ex_application_window/imp.rs

@@ -1,11 +1,9 @@
-use gtk::prelude::*;
-use gtk::subclass::prelude::*;
-use gtk::{glib, CompositeTemplate};
+use gtk::{glib, prelude::*, subclass::prelude::*};
 
 use crate::ex_menu_button::ExMenuButton;
 
 /// The private struct, which can hold widgets and other data.
-#[derive(Debug, Default, CompositeTemplate)]
+#[derive(Debug, Default, gtk::CompositeTemplate)]
 #[template(file = "ex_application_window.ui")]
 pub struct ExApplicationWindow {
     // The #[template_child] attribute tells the CompositeTemplate macro

examples/composite_template/ex_application_window/mod.rs

@@ -1,7 +1,6 @@
 mod imp;
 
-use gtk::subclass::prelude::*;
-use gtk::{gio, glib};
+use gtk::{gio, glib, subclass::prelude::*};
 
 glib::wrapper! {
     pub struct ExApplicationWindow(ObjectSubclass<imp::ExApplicationWindow>)

examples/composite_template/ex_menu_button/imp.rs

@@ -1,8 +1,6 @@
-use gtk::prelude::*;
-use gtk::subclass::prelude::*;
-use gtk::{glib, CompositeTemplate};
+use gtk::{glib, prelude::*, subclass::prelude::*};
 
-#[derive(Debug, Default, CompositeTemplate)]
+#[derive(Debug, Default, gtk::CompositeTemplate)]
 #[template(file = "ex_menu_button.ui")]
 pub struct ExMenuButton {
     #[template_child]