assistant2: Ensure errors are also displayed in populated new thread view (#27869)

Follow-up to https://github.com/zed-industries/zed/pull/27812

This PR makes sure these errors cases also show up in the panel's empty
state even when there is past data.

| No ToS | Missing Provider |
|--------|--------|
| ![CleanShot 2025-04-01 at 4  49
36@2x](https://github.com/user-attachments/assets/6da6bdc9-daa6-4a7b-a224-989eb845e205)
| ![CleanShot 2025-04-01 at 4  50
04@2x](https://github.com/user-attachments/assets/bddf62cb-3727-44b5-b115-9a88313c6d85)
|

Release Notes:

- N/A

crates/assistant2/src/assistant_panel.rs

@@ -26,7 +26,9 @@ use prompt_library::{PromptLibrary, open_prompt_library};
 use prompt_store::PromptBuilder;
 use settings::{Settings, update_settings_file};
 use time::UtcOffset;
-use ui::{ContextMenu, KeyBinding, PopoverMenu, PopoverMenuHandle, Tab, Tooltip, prelude::*};
+use ui::{
+    Banner, ContextMenu, KeyBinding, PopoverMenu, PopoverMenuHandle, Tab, Tooltip, prelude::*,
+};
 use util::ResultExt as _;
 use workspace::Workspace;
 use workspace::dock::{DockPosition, Panel, PanelEvent};
@@ -838,6 +840,7 @@ impl AssistantPanel {
         v_flex()
             .size_full()
             .when(recent_history.is_empty(), |this| {
+                let configuration_error_ref = &configuration_error;
                 this.child(
                     v_flex()
                         .size_full()
@@ -852,7 +855,8 @@ impl AssistantPanel {
                             ),
                         )
                         .when(no_error, |parent| {
-                            parent.child(
+                            parent
+                                .child(
                                     h_flex().child(
                                         Label::new("Ask and build anything.")
                                             .color(Color::Muted)
@@ -929,7 +933,7 @@ impl AssistantPanel {
                                 )
                         })
                         .map(|parent| {
-                            match configuration_error {
+                            match configuration_error_ref {
                                 Some(ConfigurationError::ProviderNotAuthenticated)
                                 | Some(ConfigurationError::NoProvider) => {
                                     parent
@@ -958,19 +962,23 @@ impl AssistantPanel {
                                                 }),
                                         )
                                 }
-                                Some(ConfigurationError::ProviderPendingTermsAcceptance(provider)) => parent
+                                Some(ConfigurationError::ProviderPendingTermsAcceptance(provider)) => {
-                                    .children(
+                                    parent.children(
                                         provider.render_accept_terms(
-                                            LanguageModelProviderTosView::ThreadEmptyState,
+                                            LanguageModelProviderTosView::ThreadFreshStart,
                                             cx,
                                         ),
-                                    ),
+                                    )
+                                }
                                 None => parent,
                             }
                         })
                 )
             })
             .when(!recent_history.is_empty(), |parent| {
+                let focus_handle = focus_handle.clone();
+                let configuration_error_ref = &configuration_error;
+
                 parent
                     .p_1p5()
                     .justify_end()
@@ -992,18 +1000,23 @@ impl AssistantPanel {
                                 Button::new("view-history", "View All")
                                     .style(ButtonStyle::Subtle)
                                     .label_size(LabelSize::Small)
-                                    .key_binding(KeyBinding::for_action_in(
+                                    .key_binding(
+                                        KeyBinding::for_action_in(
                                             &OpenHistory,
                                             &self.focus_handle(cx),
                                             window,
                                             cx,
-                                    ).map(|kb| kb.size(rems_from_px(12.))),)
+                                        ).map(|kb| kb.size(rems_from_px(12.))),
+                                    )
                                     .on_click(move |_event, window, cx| {
                                         window.dispatch_action(OpenHistory.boxed_clone(), cx);
                                     }),
                             ),
                     )
-                    .child(v_flex().gap_1().children(
+                    .child(
+                        v_flex()
+                            .gap_1()
+                            .children(
                                 recent_history.into_iter().map(|entry| {
                                     // TODO: Add keyboard navigation.
                                     match entry {
@@ -1017,7 +1030,64 @@ impl AssistantPanel {
                                         }
                                     }
                                 }),
-                    ))
+                            )
+                    )
+                    .map(|parent| {
+                        match configuration_error_ref {
+                            Some(ConfigurationError::ProviderNotAuthenticated)
+                            | Some(ConfigurationError::NoProvider) => {
+                                parent
+                                    .child(
+                                        Banner::new()
+                                            .severity(ui::Severity::Warning)
+                                            .children(
+                                                Label::new(
+                                                    "Configure at least one LLM provider to start using the panel.",
+                                                )
+                                                .size(LabelSize::Small),
+                                            )
+                                            .action_slot(
+                                                Button::new("settings", "Configure Provider")
+                                                    .style(ButtonStyle::Tinted(ui::TintColor::Warning))
+                                                    .label_size(LabelSize::Small)
+                                                    .key_binding(
+                                                        KeyBinding::for_action_in(
+                                                            &OpenConfiguration,
+                                                            &focus_handle,
+                                                            window,
+                                                            cx,
+                                                        )
+                                                        .map(|kb| kb.size(rems_from_px(12.))),
+                                                    )
+                                                    .on_click(|_event, window, cx| {
+                                                        window.dispatch_action(
+                                                            OpenConfiguration.boxed_clone(),
+                                                            cx,
+                                                        )
+                                                    }),
+                                            ),
+                                    )
+                            }
+                            Some(ConfigurationError::ProviderPendingTermsAcceptance(provider)) => {
+                                parent
+                                    .child(
+                                        Banner::new()
+                                            .severity(ui::Severity::Warning)
+                                            .children(
+                                                h_flex()
+                                                    .w_full()
+                                                    .children(
+                                                        provider.render_accept_terms(
+                                                            LanguageModelProviderTosView::ThreadtEmptyState,
+                                                            cx,
+                                                        ),
+                                                    ),
+                                            ),
+                                    )
+                            }
+                            None => parent,
+                        }
+                    })
             })
     }
 

crates/language_model/src/language_model.rs

@@ -353,7 +353,10 @@ pub trait LanguageModelProvider: 'static {
 
 #[derive(PartialEq, Eq)]
 pub enum LanguageModelProviderTosView {
-    ThreadEmptyState,
+    /// When there are some past interactions in the Agent Panel.
+    ThreadtEmptyState,
+    /// When there are no past interactions in the Agent Panel.
+    ThreadFreshStart,
     PromptEditorPopup,
     Configuration,
 }

crates/language_models/src/provider/cloud.rs

@@ -401,39 +401,30 @@ fn render_accept_terms(
 
     let accept_terms_disabled = state.read(cx).accept_terms.is_some();
 
+    let thread_fresh_start = matches!(view_kind, LanguageModelProviderTosView::ThreadFreshStart);
+    let thread_empty_state = matches!(view_kind, LanguageModelProviderTosView::ThreadtEmptyState);
+
     let terms_button = Button::new("terms_of_service", "Terms of Service")
         .style(ButtonStyle::Subtle)
         .icon(IconName::ArrowUpRight)
         .icon_color(Color::Muted)
         .icon_size(IconSize::XSmall)
+        .when(thread_empty_state, |this| this.label_size(LabelSize::Small))
         .on_click(move |_, _window, cx| cx.open_url("https://zed.dev/terms-of-service"));
 
-    let thread_view = match view_kind {
+    let button_container = h_flex().child(
-        LanguageModelProviderTosView::ThreadEmptyState => true,
-        LanguageModelProviderTosView::PromptEditorPopup => false,
-        LanguageModelProviderTosView::Configuration => false,
-    };
-
-    let form = v_flex()
-        .w_full()
-        .gap_2()
-        .child(
-            h_flex()
-                .flex_wrap()
-                .when(thread_view, |this| this.justify_center())
-                .child(Label::new(
-                    "To start using Zed AI, please read and accept the",
-                ))
-                .child(terms_button),
-        )
-        .child({
-            let button_container = h_flex().w_full().child(
         Button::new("accept_terms", "I accept the Terms of Service")
+            .when(!thread_empty_state, |this| {
+                this.full_width()
                     .style(ButtonStyle::Tinted(TintColor::Accent))
                     .icon(IconName::Check)
                     .icon_position(IconPosition::Start)
                     .icon_size(IconSize::Small)
-                    .full_width()
+            })
+            .when(thread_empty_state, |this| {
+                this.style(ButtonStyle::Tinted(TintColor::Warning))
+                    .label_size(LabelSize::Small)
+            })
             .disabled(accept_terms_disabled)
             .on_click({
                 let state = state.downgrade();
@@ -445,12 +436,48 @@ fn render_accept_terms(
             }),
     );
 
+    let form = if thread_empty_state {
+        h_flex()
+            .w_full()
+            .flex_wrap()
+            .justify_between()
+            .child(
+                h_flex()
+                    .child(
+                        Label::new("To start using Zed AI, please read and accept the")
+                            .size(LabelSize::Small),
+                    )
+                    .child(terms_button),
+            )
+            .child(button_container)
+    } else {
+        v_flex()
+            .w_full()
+            .gap_2()
+            .child(
+                h_flex()
+                    .flex_wrap()
+                    .when(thread_fresh_start, |this| this.justify_center())
+                    .child(Label::new(
+                        "To start using Zed AI, please read and accept the",
+                    ))
+                    .child(terms_button),
+            )
+            .child({
                 match view_kind {
-                LanguageModelProviderTosView::PromptEditorPopup => button_container.justify_end(),
+                    LanguageModelProviderTosView::PromptEditorPopup => {
-                LanguageModelProviderTosView::Configuration => button_container.justify_start(),
+                        button_container.w_full().justify_end()
-                LanguageModelProviderTosView::ThreadEmptyState => button_container.justify_center(),
                     }
-        });
+                    LanguageModelProviderTosView::Configuration => {
+                        button_container.w_full().justify_start()
+                    }
+                    LanguageModelProviderTosView::ThreadFreshStart => {
+                        button_container.w_full().justify_center()
+                    }
+                    LanguageModelProviderTosView::ThreadtEmptyState => div().w_0(),
+                }
+            })
+    };
 
     Some(form.into_any())
 }

crates/ui/src/components/banner.rs

@@ -130,7 +130,7 @@ impl RenderOnce for Banner {
                 .child(content_area)
                 .child(action_slot);
         } else {
-            container = container.px_2().child(content_area);
+            container = container.px_2().child(div().w_full().child(content_area));
         }
 
         container