server_list: implement server deletion, fixes #355 (#361)

Adds a delete_server screen to delete servers, handled by clicking
the "X" button on the server list, similar to the "E" button for edit_server.

src/screen/delete_server.rs

@@ -0,0 +1,157 @@
+// Copyright 2016 Matthew Collins
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use std::collections::BTreeMap;
+use std_or_web::fs;
+
+use crate::render;
+use crate::ui;
+
+use serde_json::{self, Value};
+
+pub struct DeleteServerEntry {
+    elements: Option<UIElements>,
+    index: usize,
+    name: String,
+    address: String,
+}
+
+struct UIElements {
+    logo: ui::logo::Logo,
+
+    _prompt: ui::TextRef,
+    _confirm: ui::ButtonRef,
+    _cancel: ui::ButtonRef,
+}
+
+impl DeleteServerEntry {
+    pub fn new(index: usize, name: &str, address: &str) -> DeleteServerEntry {
+        DeleteServerEntry {
+            elements: None,
+            index,
+            name: name.to_string(),
+            address: address.to_string(),
+        }
+    }
+
+    fn delete_server(index: usize) {
+        let mut servers_info = match fs::File::open("servers.json") {
+            Ok(val) => serde_json::from_reader(val).unwrap(),
+            Err(_) => {
+                let mut info = BTreeMap::default();
+                info.insert("servers".to_owned(), Value::Array(vec![]));
+                Value::Object(info.into_iter().collect())
+            }
+        };
+
+        {
+            let servers = servers_info
+                .as_object_mut()
+                .unwrap()
+                .get_mut("servers")
+                .unwrap()
+                .as_array_mut()
+                .unwrap();
+            servers.remove(index);
+        }
+
+        let mut out = fs::File::create("servers.json").unwrap();
+        serde_json::to_writer_pretty(&mut out, &servers_info).unwrap();
+    }
+}
+
+impl super::Screen for DeleteServerEntry {
+    fn on_active(&mut self, renderer: &mut render::Renderer, ui_container: &mut ui::Container) {
+        let logo = ui::logo::Logo::new(renderer.resources.clone(), ui_container);
+
+        // Prompt
+        let prompt = ui::TextBuilder::new()
+            .text(format!(
+                "Are you sure you wish to delete {} {}?",
+                self.name, self.address
+            ))
+            .position(0.0, 40.0)
+            .alignment(ui::VAttach::Middle, ui::HAttach::Center)
+            .create(ui_container);
+
+        // Confirm
+        let confirm = ui::ButtonBuilder::new()
+            .position(110.0, 100.0)
+            .size(200.0, 40.0)
+            .alignment(ui::VAttach::Middle, ui::HAttach::Center)
+            .create(ui_container);
+        {
+            let mut confirm = confirm.borrow_mut();
+            let txt = ui::TextBuilder::new()
+                .text("Confirm")
+                .alignment(ui::VAttach::Middle, ui::HAttach::Center)
+                .attach(&mut *confirm);
+            confirm.add_text(txt);
+            let index = self.index;
+            confirm.add_click_func(move |_, game| {
+                Self::delete_server(index);
+                game.screen_sys
+                    .replace_screen(Box::new(super::ServerList::new(None)));
+                true
+            });
+        }
+
+        // Cancel
+        let cancel = ui::ButtonBuilder::new()
+            .position(-110.0, 100.0)
+            .size(200.0, 40.0)
+            .alignment(ui::VAttach::Middle, ui::HAttach::Center)
+            .create(ui_container);
+        {
+            let mut cancel = cancel.borrow_mut();
+            let txt = ui::TextBuilder::new()
+                .text("Cancel")
+                .alignment(ui::VAttach::Middle, ui::HAttach::Center)
+                .attach(&mut *cancel);
+            cancel.add_text(txt);
+            cancel.add_click_func(|_, game| {
+                game.screen_sys
+                    .replace_screen(Box::new(super::ServerList::new(None)));
+                true
+            });
+        }
+
+        self.elements = Some(UIElements {
+            logo,
+            _prompt: prompt,
+            _confirm: confirm,
+            _cancel: cancel,
+        });
+    }
+
+    fn on_deactive(&mut self, _renderer: &mut render::Renderer, _ui_container: &mut ui::Container) {
+        // Clean up
+        self.elements = None
+    }
+
+    fn tick(
+        &mut self,
+        _delta: f64,
+        renderer: &mut render::Renderer,
+        _ui_container: &mut ui::Container,
+    ) -> Option<Box<dyn super::Screen>> {
+        let elements = self.elements.as_mut().unwrap();
+        elements.logo.tick(renderer);
+        None
+    }
+
+    fn is_closable(&self) -> bool {
+        true
+    }
+}

src/screen/mod.rs

@@ -18,6 +18,7 @@ mod login;
 pub use self::login::*;
 
 pub mod connecting;
+pub mod delete_server;
 pub mod edit_server;
 
 pub mod settings_menu;

src/screen/server_list.rs

@@ -207,6 +207,15 @@ impl ServerList {
                     .alignment(ui::VAttach::Middle, ui::HAttach::Center)
                     .attach(&mut *btn);
                 btn.add_text(txt);
+                let index = index;
+                let sname = name.clone();
+                let saddr = address.clone();
+                btn.add_click_func(move |_, game| {
+                    game.screen_sys.replace_screen(Box::new(
+                        super::delete_server::DeleteServerEntry::new(index, &sname, &saddr),
+                    ));
+                    true
+                })
             }
 
             // Edit entry button