general: Add fullscreen widget

src/widgets/fullscreen_widget.rs

@@ -0,0 +1,147 @@
+// Copyright (c) 2024 Christopher Davis
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+use std::cell::{Cell, RefCell};
+
+use adw::prelude::*;
+use adw::subclass::prelude::*;
+use glib::Properties;
+use gtk::CompositeTemplate;
+
+use super::*;
+use crate::deps::*;
+
+mod imp {
+    use super::*;
+
+    #[derive(Default, Debug, Properties, CompositeTemplate)]
+    #[properties(wrapper_type = super::LpFullscreenWidget)]
+    #[template(file = "fullscreen_widget.ui")]
+    pub struct LpFullscreenWidget {
+        #[template_child]
+        pub(super) toolbar_view: TemplateChild<adw::ToolbarView>,
+        #[template_child]
+        pub(super) header_container: TemplateChild<LpShyBin>,
+
+        #[property(get, set, nullable)]
+        headerbar: RefCell<Option<gtk::Widget>>,
+        #[property(get, set, nullable)]
+        content: RefCell<Option<gtk::Widget>>,
+
+        #[property(get, set)]
+        fullscreened: Cell<bool>,
+        #[property(get, set)]
+        extend_content: Cell<bool>,
+        #[property(get = LpFullscreenWidget::is_content_extended_to_top, type = bool)]
+        _is_content_extended_to_top: (),
+        #[property(get, set)]
+        is_empty: Cell<bool>,
+        #[property(get, set)]
+        headerbar_opacity: Cell<f64>,
+    }
+
+    impl LpFullscreenWidget {
+        fn is_content_extended_to_top(&self) -> bool {
+            let obj = self.obj();
+            obj.fullscreened() && obj.extend_content()
+        }
+    }
+
+    #[glib::object_subclass]
+    impl ObjectSubclass for LpFullscreenWidget {
+        const NAME: &'static str = "LpFullscreenWidget";
+        type Type = super::LpFullscreenWidget;
+        type ParentType = adw::Bin;
+
+        fn class_init(klass: &mut Self::Class) {
+            klass.bind_template();
+        }
+
+        fn instance_init(obj: &gio::glib::subclass::InitializingObject<Self>) {
+            obj.init_template();
+        }
+    }
+
+    #[glib::derived_properties]
+    impl ObjectImpl for LpFullscreenWidget {
+        fn constructed(&self) {
+            self.parent_constructed();
+
+            let obj = self.obj();
+            obj.connect_is_empty_notify(|obj| {
+                obj.update_headerbar_style();
+            });
+
+            obj.connect_fullscreened_notify(|obj| {
+                obj.update_headerbar_style();
+            });
+
+            obj.connect_extend_content_notify(|obj| {
+                obj.update_headerbar_style();
+            });
+        }
+    }
+
+    impl WidgetImpl for LpFullscreenWidget {}
+    impl BinImpl for LpFullscreenWidget {}
+}
+
+glib::wrapper! {
+    pub struct LpFullscreenWidget(ObjectSubclass<imp::LpFullscreenWidget>)
+        @extends gtk::Widget, adw::Bin,
+        @implements gtk::Buildable, gtk::ConstraintTarget;
+}
+
+impl LpFullscreenWidget {
+    pub fn is_headerbar_flat(&self) -> bool {
+        matches!(
+            self.imp().toolbar_view.top_bar_style(),
+            adw::ToolbarStyle::Flat
+        )
+    }
+
+    fn update_header_opacity(&self) {
+        if let Some(headerbar) = self.headerbar() {
+            if self.is_headerbar_flat() && !self.is_empty() {
+                // Bring headerbar opacity in sync with controls
+                headerbar.set_opacity(self.headerbar_opacity());
+            } else {
+                headerbar.set_opacity(1.);
+            };
+        }
+    }
+
+    fn update_headerbar_style(&self) {
+        self.imp()
+            .toolbar_view
+            .set_extend_content_to_top_edge(self.is_content_extended_to_top());
+
+        // Flat headerbar for empty state and fullscreen
+        let style = if self.is_empty() || self.is_content_extended_to_top() {
+            adw::ToolbarStyle::Flat
+        } else {
+            // Use the border variant of raised to avoid shadows over images
+            adw::ToolbarStyle::RaisedBorder
+        };
+
+        let toolbar_view = self.imp().toolbar_view.get();
+        if style != toolbar_view.top_bar_style() {
+            toolbar_view.set_top_bar_style(style);
+            self.update_header_opacity();
+        }
+    }
+}

src/widgets/fullscreen_widget.ui

@@ -0,0 +1,30 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<interface>
+  <template class="LpFullscreenWidget" parent="AdwBin">
+    <binding name="fullscreened">
+      <lookup name="fullscreened" type="GtkWindow">
+        <lookup name="root">LpFullscreenWidget</lookup>
+      </lookup>
+    </binding>
+    <binding name="is-empty">
+      <lookup name="is-empty" type="LpWindow">
+        <lookup name="root">LpFullscreenWidget</lookup>
+      </lookup>
+    </binding>
+    <binding name="headerbar-opacity">
+      <lookup name="headerbar-opacity" type="LpWindow">
+        <lookup name="root">LpFullscreenWidget</lookup>
+      </lookup>
+    </binding>
+    <property name="child">
+      <object class="AdwToolbarView" id="toolbar_view">
+        <child type="top">
+          <object class="LpShyBin" id="header_container">
+            <property name="child" bind-source="LpFullscreenWidget" bind-property="headerbar"/>
+          </object>
+        </child>
+        <property name="content" bind-source="LpFullscreenWidget" bind-property="content"/>
+      </object>
+    </property>
+  </template>
+</interface>