better error handling

examples/embedded_webview.rs

@@ -17,11 +17,11 @@ fn main() -> iced::Result {
 #[derive(Debug, Clone)]
 enum Message {
     WebView(Action),
-    ToggleWebviewVisibility,
+    ToggleWebview,
     UrlChanged(String),
-    NewWebViewCreated,
+    WebviewCreated,
     CreateWebview,
-    SwitchWebview,
+    CycleWebview,
 }
 
 struct App {
@@ -35,7 +35,7 @@ struct App {
 impl App {
     fn new() -> (Self, Task<Message>) {
         let webview = WebView::new()
-            .on_create_view(Message::NewWebViewCreated)
+            .on_create_view(Message::WebviewCreated)
             .on_url_change(Message::UrlChanged);
         (
             Self {
@@ -52,28 +52,27 @@ impl App {
 
     fn update(&mut self, message: Message) -> Task<Message> {
         match message {
-            Message::NewWebViewCreated => {
+            Message::WebView(msg) => self.webview.update(msg),
+            Message::CreateWebview => self
+                .webview
+                .update(Action::CreateView(PageType::Url(URL.to_string()))),
+            Message::WebviewCreated => {
                 if self.current_view == None {
-                    self.current_view = Some(0);
                     // if its the first tab change to it, after that require switching manually
-                    return Task::done(Action::ChangeView(0)).map(Message::WebView);
+                    return Task::done(Message::CycleWebview);
                 }
                 self.num_views += 1;
                 Task::none()
             }
-            Message::WebView(msg) => self.webview.update(msg),
-            Message::ToggleWebviewVisibility => {
+            Message::ToggleWebview => {
                 self.show_webview = !self.show_webview;
                 Task::none()
             }
             Message::UrlChanged(new_url) => {
                 self.webview_url = Some(new_url);
                 Task::none()
             }
-            Message::CreateWebview => self
-                .webview
-                .update(Action::CreateView(PageType::Url(URL.to_string()))),
-            Message::SwitchWebview => {
+            Message::CycleWebview => {
                 if let Some(current_view) = self.current_view.as_mut() {
                     if *current_view + 1 > self.num_views {
                         *current_view = 0;
@@ -82,7 +81,8 @@ impl App {
                     };
                     self.webview.update(Action::ChangeView(*current_view))
                 } else {
-                    Task::none()
+                    self.current_view = Some(0);
+                    self.webview.update(Action::ChangeView(0))
                 }
             }
         }
@@ -96,9 +96,9 @@ impl App {
                 "Iced docs can be pulled up inside an iced app?! Whoa!"
             }),
             container(row![
-                button("Toggle web view(s)").on_press(Message::ToggleWebviewVisibility),
+                button("Toggle web view(s)").on_press(Message::ToggleWebview),
                 button("New web view").on_press(Message::CreateWebview),
-                button("Switch views").on_press(Message::SwitchWebview),
+                button("Switch views").on_press(Message::CycleWebview),
             ])
             .align_right(Length::Fill)
         ]];

src/engines.rs

@@ -14,6 +14,15 @@ pub enum PixelFormat {
     Bgra,
 }
 
+/// Result type for get_url, get_title, get_view, and get_cursor
+/// This is because they can fail by the wrong id, and the requested view, may not be loaded yet
+#[derive(Debug, Clone)]
+pub enum EngineResult<T> {
+    IdDoesNotExist,
+    NotLoaded,
+    Success(T),
+}
+
 /// Alias of usize used for controlling specific views
 /// Only used by advanced to get views, basic simply uses u32
 pub type ViewId = usize;
@@ -35,7 +44,7 @@ pub trait Engine {
     /// Can fail if requested id does not exist
     fn remove_view(&mut self, id: ViewId) -> Option<()>;
 
-    // window changes - no id needed they work for all views
+    // window changes - no id needed they work for all views(gloabally)
     fn focus(&mut self);
     fn unfocus(&self);
     fn resize(&mut self, size: Size<u32>);
@@ -59,13 +68,13 @@ pub trait Engine {
     fn scroll(&mut self, id: ViewId, delta: mouse::ScrollDelta) -> Option<()>;
 
     /// Can fail if requested id does not exist or page has not loaded and therfore has no url
-    fn get_url(&self, id: ViewId) -> Option<String>;
+    fn get_url(&self, id: ViewId) -> EngineResult<String>;
     /// Can fail if requested id does not exist or page has not loaded and therfore has no title
-    fn get_title(&self, id: ViewId) -> Option<String>;
+    fn get_title(&self, id: ViewId) -> EngineResult<String>;
     /// Can fail if requested id does not exist
-    fn get_view(&self, id: ViewId) -> Option<&ImageInfo>;
+    fn get_cursor(&self, id: ViewId) -> EngineResult<Interaction>;
     /// Can fail if requested id does not exist
-    fn get_cursor(&self, id: ViewId) -> Option<Interaction>;
+    fn get_view(&self, id: ViewId) -> EngineResult<&ImageInfo>;
 }
 
 /// Allows users to create new views with url or custom html

src/engines/ultralight.rs

@@ -19,10 +19,9 @@ use ul_next::{
     Surface,
 };
 
+use super::{Engine, EngineResult, PageType, PixelFormat, ViewId};
 use crate::ImageInfo;
 
-use super::{Engine, PageType, PixelFormat, ViewId};
-
 struct UlClipboard {
     ctx: ClipboardContext,
 }
@@ -386,26 +385,49 @@ impl Engine for Ultralight {
         Some(())
     }
 
-    fn get_url(&self, id: ViewId) -> Option<String> {
-        self.get_view(id)?.view.url().ok()
+    fn get_url(&self, id: ViewId) -> EngineResult<String> {
+        if let Some(view) = self.get_view(id) {
+            match view.view.url() {
+                Ok(url) => EngineResult::Success(url),
+                Err(_) => EngineResult::NotLoaded,
+            }
+        } else {
+            EngineResult::IdDoesNotExist
+        }
     }
 
-    fn get_title(&self, id: ViewId) -> Option<String> {
-        self.get_view(id)?.view.title().ok()
+    fn get_title(&self, id: ViewId) -> EngineResult<String> {
+        if let Some(view) = self.get_view(id) {
+            match view.view.title() {
+                Ok(title) => EngineResult::Success(title),
+                Err(_) => EngineResult::NotLoaded,
+            }
+        } else {
+            EngineResult::IdDoesNotExist
+        }
     }
 
-    fn get_view(&self, id: ViewId) -> Option<&ImageInfo> {
-        Some(&self.get_view(id)?.last_frame)
+    fn get_cursor(&self, id: ViewId) -> EngineResult<mouse::Interaction> {
+        if let Some(view) = self.get_view(id) {
+            match view.cursor.read() {
+                Ok(cursor) => EngineResult::Success(*cursor),
+                Err(_) => EngineResult::NotLoaded,
+            }
+        } else {
+            EngineResult::IdDoesNotExist
+        }
     }
 
-    fn get_cursor(&self, id: ViewId) -> Option<mouse::Interaction> {
-        Some(
-            *self
-                .get_view(id)?
-                .cursor
-                .read()
-                .expect("Failed to get Ultraights cursor status"),
-        )
+    fn get_view(&self, id: ViewId) -> EngineResult<&ImageInfo> {
+        if let Some(view) = self.get_view(id) {
+            if self.get_view(id).unwrap().view.is_loading() {
+                EngineResult::NotLoaded
+            } else {
+                EngineResult::Success(&view.last_frame)
+            }
+        } else {
+            EngineResult::IdDoesNotExist
+        }
     }
 }
 

src/webview/advanced.rs

@@ -15,6 +15,7 @@ use iced::{Element, Point, Size, Task};
 use url::Url;
 
 use crate::{engines, ImageInfo, PageType, ViewId};
+use engines::EngineResult;
 
 #[derive(Debug, Clone, PartialEq)]
 pub enum Action {
@@ -99,7 +100,7 @@ impl<Engine: engines::Engine + Default, Message: Send + Clone + 'static> WebView
         // Check url & title for changes and callback if so
         for (id, url) in self.urls.iter_mut() {
             if let Some(on_url_change) = &self.on_url_change {
-                if let Some(engine_url) = self.engine.get_url(*id) {
+                if let EngineResult::Success(engine_url) = self.engine.get_url(*id) {
                     if *url != engine_url {
                         *url = engine_url.clone();
                         tasks.push(Task::done(on_url_change(*id, engine_url)));
@@ -109,7 +110,7 @@ impl<Engine: engines::Engine + Default, Message: Send + Clone + 'static> WebView
         }
         for (id, title) in self.titles.iter_mut() {
             if let Some(on_title_change) = &self.on_title_change {
-                if let Some(engine_title) = self.engine.get_title(*id) {
+                if let EngineResult::Success(engine_title) = self.engine.get_title(*id) {
                     if *title != engine_title {
                         *title = engine_title.clone();
                         tasks.push(Task::done(on_title_change(*id, engine_title)));
@@ -186,17 +187,33 @@ impl<Engine: engines::Engine + Default, Message: Send + Clone + 'static> WebView
 
     /// Like a normal `view()` method in iced, but takes an id of the desired view
     pub fn view(&self, id: usize) -> Element<Action> {
-        WebViewWidget::new(
-            id,
-            self.view_size,
-            self.engine
-                .get_view(id)
-                .expect("Failed to get view with that id"),
-            self.engine
-                .get_cursor(id)
-                .expect("Failed to get view with that id"),
-        )
-        .into()
+        let view = match self.engine.get_view(id) {
+            EngineResult::IdDoesNotExist => panic!("Requested Id does not exist"),
+            EngineResult::NotLoaded => {
+                return WebViewWidget::new(
+                    id,
+                    self.view_size,
+                    &ImageInfo::default(),
+                    Interaction::None,
+                )
+                .into()
+            }
+            EngineResult::Success(view) => view,
+        };
+        let cursor = match self.engine.get_cursor(id) {
+            EngineResult::IdDoesNotExist => panic!("Requested Id does not exist"),
+            EngineResult::NotLoaded => {
+                return WebViewWidget::new(
+                    id,
+                    self.view_size,
+                    &ImageInfo::default(),
+                    Interaction::None,
+                )
+                .into()
+            }
+            EngineResult::Success(cursor) => cursor,
+        };
+        WebViewWidget::new(id, self.view_size, view, cursor).into()
     }
 }
 

src/webview/basic.rs

@@ -15,6 +15,7 @@ use iced::{Element, Point, Size, Task};
 use url::Url;
 
 use crate::{engines, ImageInfo, PageType, ViewId};
+use engines::EngineResult;
 
 #[derive(Debug, Clone, PartialEq)]
 pub enum Action {
@@ -127,15 +128,18 @@ impl<Engine: engines::Engine + Default, Message: Send + Clone + 'static> WebView
 
         if self.current_view_index.is_some() {
             if let Some(on_url_change) = &self.on_url_change {
-                if let Some(url) = self.engine.get_url(self.get_current_view_id()) {
+                if let EngineResult::Success(url) = self.engine.get_url(self.get_current_view_id())
+                {
                     if self.url != url {
                         self.url = url.clone();
                         tasks.push(Task::done(on_url_change(url)))
                     }
                 }
             }
             if let Some(on_title_change) = &self.on_title_change {
-                if let Some(title) = self.engine.get_title(self.get_current_view_id()) {
+                if let EngineResult::Success(title) =
+                    self.engine.get_title(self.get_current_view_id())
+                {
                     if self.title != title {
                         self.title = title.clone();
                         tasks.push(Task::done(on_title_change(title)))
@@ -225,16 +229,23 @@ impl<Engine: engines::Engine + Default, Message: Send + Clone + 'static> WebView
 
     /// Returns webview widget for the current view
     pub fn view(&self) -> Element<Action> {
-        WebViewWidget::new(
-            self.view_size,
-            self.engine
-                .get_view(self.get_current_view_id())
-                .expect("failed to get view, because current view id does not exist"),
-            self.engine
-                .get_cursor(self.get_current_view_id())
-                .expect("failed to get view, because current view id does not exist"),
-        )
-        .into()
+        let view = match self.engine.get_view(self.get_current_view_id()) {
+            EngineResult::IdDoesNotExist => panic!("Requested Id does not exist"),
+            EngineResult::NotLoaded => {
+                return WebViewWidget::new(self.view_size, &ImageInfo::default(), Interaction::None)
+                    .into()
+            }
+            EngineResult::Success(view) => view,
+        };
+        let cursor = match self.engine.get_cursor(self.get_current_view_id()) {
+            EngineResult::IdDoesNotExist => panic!("Requested Id does not exist"),
+            EngineResult::NotLoaded => {
+                return WebViewWidget::new(self.view_size, &ImageInfo::default(), Interaction::None)
+                    .into()
+            }
+            EngineResult::Success(cursor) => cursor,
+        };
+        WebViewWidget::new(self.view_size, view, cursor).into()
     }
 }