Click file paths to open in editor, allow plugins to change styles and hover of viewport (#4802)

* initial implementation

* implement hover

* add styles and foreground/background emphases, fix upsert hover collisions

* initial implementation of link plugin

* suppress highlighting + clicks on unfocused and mouse mode panes

* also make italic

* fix env var and ~ expansions

* fix regex issues and add defensive validations

* fix tests and add plugin assets

* add tests

* refactor all the things

* add pr

4 files changed, 310 insertions, 21 deletions

diff --git a/zellij-utils/src/plugin_api/event.proto b/zellij-utils/src/plugin_api/event.proto
index bbee50a3..ce018a7f 100644
--- a/zellij-utils/src/plugin_api/event.proto
+++ b/zellij-utils/src/plugin_api/event.proto
@@ -64,6 +64,7 @@ enum EventType {
     CwdChanged = 39;
     AvailableLayoutInfo = 40;
     PluginConfigurationChanged = 41;
+    HighlightClicked = 42;
 }
 
 message EventNameList {
@@ -107,6 +108,7 @@ message Event {
     CwdChangedPayload cwd_changed_payload = 33;
     AvailableLayoutInfoPayload available_layout_info_payload = 34;
     PluginConfigurationChangedPayload plugin_configuration_changed_payload = 35;
+    HighlightClickedPayload highlight_clicked_payload = 36;
   }
 }
 
@@ -516,3 +518,10 @@ message PluginConfigurationChangedPayload {
   repeated ContextItem configuration = 1;
 }
 
+message HighlightClickedPayload {
+  PaneId pane_id = 1;
+  string pattern = 2;
+  string matched_string = 3;
+  repeated ContextItem context = 4;
+}
+
diff --git a/zellij-utils/src/plugin_api/event.rs b/zellij-utils/src/plugin_api/event.rs
index 631d5069..267e1357 100644
--- a/zellij-utils/src/plugin_api/event.rs
+++ b/zellij-utils/src/plugin_api/event.rs
@@ -500,6 +500,26 @@ impl TryFrom<ProtobufEvent> for Event {
                 },
                 _ => Err("Malformed payload for PluginConfigurationChanged Event"),
             },
+            Some(ProtobufEventType::HighlightClicked) => match protobuf_event.payload {
+                Some(ProtobufEventPayload::HighlightClickedPayload(p)) => {
+                    let pane_id = p
+                        .pane_id
+                        .ok_or("Missing pane_id in HighlightClicked")?
+                        .try_into()?;
+                    let context = p
+                        .context
+                        .into_iter()
+                        .map(|item| (item.name, item.value))
+                        .collect();
+                    Ok(Event::HighlightClicked {
+                        pane_id,
+                        pattern: p.pattern,
+                        matched_string: p.matched_string,
+                        context,
+                    })
+                },
+                _ => Err("Malformed payload for HighlightClicked Event"),
+            },
             None => Err("Unknown Protobuf Event"),
         }
     }
@@ -991,6 +1011,25 @@ impl TryFrom<Event> for ProtobufEvent {
                     payload: Some(event::Payload::PluginConfigurationChangedPayload(payload)),
                 })
             },
+            Event::HighlightClicked {
+                pane_id,
+                pattern,
+                matched_string,
+                context,
+            } => Ok(ProtobufEvent {
+                name: ProtobufEventType::HighlightClicked as i32,
+                payload: Some(event::Payload::HighlightClickedPayload(
+                    HighlightClickedPayload {
+                        pane_id: pane_id.try_into().ok(),
+                        pattern,
+                        matched_string,
+                        context: context
+                            .into_iter()
+                            .map(|(name, value)| ProtobufContextItem { name, value })
+                            .collect(),
+                    },
+                )),
+            }),
         }
     }
 }
@@ -1901,6 +1940,7 @@ impl TryFrom<ProtobufEventType> for EventType {
             ProtobufEventType::CwdChanged => EventType::CwdChanged,
             ProtobufEventType::AvailableLayoutInfo => EventType::AvailableLayoutInfo,
             ProtobufEventType::PluginConfigurationChanged => EventType::PluginConfigurationChanged,
+            ProtobufEventType::HighlightClicked => EventType::HighlightClicked,
         })
     }
 }
@@ -1950,6 +1990,7 @@ impl TryFrom<EventType> for ProtobufEventType {
             EventType::CwdChanged => ProtobufEventType::CwdChanged,
             EventType::AvailableLayoutInfo => ProtobufEventType::AvailableLayoutInfo,
             EventType::PluginConfigurationChanged => ProtobufEventType::PluginConfigurationChanged,
+            EventType::HighlightClicked => ProtobufEventType::HighlightClicked,
         })
     }
 }
diff --git a/zellij-utils/src/plugin_api/plugin_command.proto b/zellij-utils/src/plugin_api/plugin_command.proto
index 53e9d729..c4fa949f 100644
--- a/zellij-utils/src/plugin_api/plugin_command.proto
+++ b/zellij-utils/src/plugin_api/plugin_command.proto
@@ -199,6 +199,8 @@ enum CommandName {
   HideFloatingPanes = 204;
   ShowFloatingPanes = 205;
   SetPaneColor = 206;
+  SetPaneRegexHighlights = 207;
+  ClearPaneHighlights = 208;
 }
 
 message PluginCommand {
@@ -347,6 +349,8 @@ message PluginCommand {
     HideFloatingPanesPayload hide_floating_panes_payload = 155;
     ShowFloatingPanesPayload show_floating_panes_payload = 156;
     SetPaneColorPayload set_pane_color_payload = 157;
+    SetPaneRegexHighlightsPayload set_pane_regex_highlights_payload = 158;
+    ClearPaneHighlightsPayload clear_pane_highlights_payload = 159;
   }
 }
 
@@ -1220,3 +1224,52 @@ message SetPaneColorPayload {
   optional string fg = 2;
   optional string bg = 3;
 }
+
+message HighlightStyle {
+  oneof style {
+    bool emphasis_0 = 1;
+    bool emphasis_1 = 2;
+    bool emphasis_2 = 3;
+    bool emphasis_3 = 4;
+    CustomRgbHighlight custom_rgb = 5;
+    CustomIndexHighlight custom_index = 6;
+    bool background_emphasis_0 = 7;
+    bool background_emphasis_1 = 8;
+    bool background_emphasis_2 = 9;
+    bool background_emphasis_3 = 10;
+    bool none = 11;
+  }
+}
+
+message CustomRgbHighlight {
+  optional uint32 fg_r = 1;
+  optional uint32 fg_g = 2;
+  optional uint32 fg_b = 3;
+  optional uint32 bg_r = 4;
+  optional uint32 bg_g = 5;
+  optional uint32 bg_b = 6;
+}
+
+message CustomIndexHighlight {
+  optional uint32 fg = 1;
+  optional uint32 bg = 2;
+}
+
+message RegexHighlight {
+  string pattern = 1;
+  HighlightStyle style = 2;
+  repeated ContextItem context = 3;
+  bool on_hover = 4;
+  bool bold = 5;
+  bool italic = 6;
+  bool underline = 7;
+}
+
+message SetPaneRegexHighlightsPayload {
+  PaneId pane_id = 1;
+  repeated RegexHighlight highlights = 2;
+}
+
+message ClearPaneHighlightsPayload {
+  PaneId pane_id = 1;
+}
diff --git a/zellij-utils/src/plugin_api/plugin_command.rs b/zellij-utils/src/plugin_api/plugin_command.rs
index abd9a994..b535e14a 100644
--- a/zellij-utils/src/plugin_api/plugin_command.rs
+++ b/zellij-utils/src/plugin_api/plugin_command.rs
@@ -7,7 +7,8 @@ pub use super::generated_api::api::{
         break_panes_to_tab_with_index_response, delete_layout_response, dump_layout_response,
         dump_session_layout_response, edit_layout_response, focus_or_create_tab_response,
         get_focused_pane_info_response, get_pane_cwd_response, get_pane_pid_response,
-        get_pane_running_command_response, hide_floating_panes_response, new_tab_response,
+        get_pane_running_command_response, hide_floating_panes_response,
+        highlight_style::Style as ProtobufHighlightStyleVariant, new_tab_response,
         parse_layout_response, plugin_command::Payload, rename_layout_response,
         save_layout_response, save_session_response, show_floating_panes_response,
         BreakPanesToNewTabPayload,
@@ -16,17 +17,19 @@ pub use super::generated_api::api::{
         BreakPanesToTabWithIdResponse as ProtobufBreakPanesToTabWithIdResponse,
         BreakPanesToTabWithIndexPayload,
         BreakPanesToTabWithIndexResponse as ProtobufBreakPanesToTabWithIndexResponse,
-        ChangeFloatingPanesCoordinatesPayload, ChangeHostFolderPayload,
+        ChangeFloatingPanesCoordinatesPayload, ChangeHostFolderPayload, ClearPaneHighlightsPayload,
         ClearScreenForPaneIdPayload, CliPipeOutputPayload, CloseMultiplePanesPayload,
         CloseTabWithIdPayload, CloseTabWithIndexPayload, CommandName, ContextItem,
         CopyToClipboardPayload, CreateTokenResponse as ProtobufCreateTokenResponse,
         CreateTokenResponse, CurrentSessionLastSavedTimePayload,
         CurrentSessionLastSavedTimeResponse as ProtobufCurrentSessionLastSavedTimeResponse,
-        CursorPosition, DeleteLayoutPayload, DeleteLayoutResponse as ProtobufDeleteLayoutResponse,
-        DumpLayoutPayload, DumpLayoutResponse as ProtobufDumpLayoutResponse,
-        DumpSessionLayoutPayload, DumpSessionLayoutResponse as ProtobufDumpSessionLayoutResponse,
-        EditLayoutPayload, EditLayoutResponse as ProtobufEditLayoutResponse,
-        EditScrollbackForPaneWithIdPayload, EmbedMultiplePanesPayload, EnvVariable, ExecCmdPayload,
+        CursorPosition, CustomIndexHighlight as ProtobufCustomIndexHighlight,
+        CustomRgbHighlight as ProtobufCustomRgbHighlight, DeleteLayoutPayload,
+        DeleteLayoutResponse as ProtobufDeleteLayoutResponse, DumpLayoutPayload,
+        DumpLayoutResponse as ProtobufDumpLayoutResponse, DumpSessionLayoutPayload,
+        DumpSessionLayoutResponse as ProtobufDumpSessionLayoutResponse, EditLayoutPayload,
+        EditLayoutResponse as ProtobufEditLayoutResponse, EditScrollbackForPaneWithIdPayload,
+        EmbedMultiplePanesPayload, EnvVariable, ExecCmdPayload,
         FixedOrPercent as ProtobufFixedOrPercent,
         FixedOrPercentValue as ProtobufFixedOrPercentValue, FloatMultiplePanesPayload,
         FloatingPaneCoordinates as ProtobufFloatingPaneCoordinates,
@@ -48,10 +51,11 @@ pub use super::generated_api::api::{
         GetTabInfoPayload, GetTabInfoResponse as ProtobufGetTabInfoResponse, GoToTabWithIdPayload,
         GroupAndUngroupPanesPayload, HideFloatingPanesPayload as ProtobufHideFloatingPanesPayload,
         HideFloatingPanesResponse as ProtobufHideFloatingPanesResponse, HidePaneWithIdPayload,
-        HighlightAndUnhighlightPanesPayload, HttpVerb as ProtobufHttpVerb, IdAndNewName,
-        KeyToRebind, KeyToUnbind, KillSessionsPayload, ListTokensResponse, LoadNewPluginPayload,
-        MessageToPluginPayload, MovePaneWithPaneIdInDirectionPayload, MovePaneWithPaneIdPayload,
-        MovePayload, NewPluginArgs as ProtobufNewPluginArgs, NewTabPayload,
+        HighlightAndUnhighlightPanesPayload, HighlightStyle as ProtobufHighlightStyle,
+        HttpVerb as ProtobufHttpVerb, IdAndNewName, KeyToRebind, KeyToUnbind, KillSessionsPayload,
+        ListTokensResponse, LoadNewPluginPayload, MessageToPluginPayload,
+        MovePaneWithPaneIdInDirectionPayload, MovePaneWithPaneIdPayload, MovePayload,
+        NewPluginArgs as ProtobufNewPluginArgs, NewTabPayload,
         NewTabResponse as ProtobufNewTabResponse, NewTabsResponse as ProtobufNewTabsResponse,
         NewTabsWithLayoutInfoPayload,
         OpenCommandPaneBackgroundResponse as ProtobufOpenCommandPaneBackgroundResponse,
@@ -92,19 +96,19 @@ pub use super::generated_api::api::{
         PageScrollDownInPaneIdPayload, PageScrollUpInPaneIdPayload, PaneId as ProtobufPaneId,
         PaneIdAndFloatingPaneCoordinates, PaneType as ProtobufPaneType, ParseLayoutPayload,
         ParseLayoutResponse as ProtobufParseLayoutResponse, PluginCommand as ProtobufPluginCommand,
-        PluginMessagePayload, RebindKeysPayload, ReconfigurePayload, ReloadPluginPayload,
-        RenameLayoutPayload, RenameLayoutResponse as ProtobufRenameLayoutResponse,
-        RenameTabWithIdPayload, RenameWebLoginTokenPayload, RenameWebTokenResponse,
-        ReplacePaneWithExistingPanePayload, RequestPluginPermissionPayload,
-        RerunCommandPanePayload, ResizePaneIdWithDirectionPayload, ResizePayload,
-        RevokeAllWebTokensResponse, RevokeTokenResponse, RevokeWebLoginTokenPayload,
+        PluginMessagePayload, RebindKeysPayload, ReconfigurePayload,
+        RegexHighlight as ProtobufRegexHighlight, ReloadPluginPayload, RenameLayoutPayload,
+        RenameLayoutResponse as ProtobufRenameLayoutResponse, RenameTabWithIdPayload,
+        RenameWebLoginTokenPayload, RenameWebTokenResponse, ReplacePaneWithExistingPanePayload,
+        RequestPluginPermissionPayload, RerunCommandPanePayload, ResizePaneIdWithDirectionPayload,
+        ResizePayload, RevokeAllWebTokensResponse, RevokeTokenResponse, RevokeWebLoginTokenPayload,
         RunActionPayload, RunCommandPayload, RunningCommand as ProtobufRunningCommand,
         SaveLayoutPayload, SaveLayoutResponse as ProtobufSaveLayoutResponse, SaveSessionPayload,
         SaveSessionResponse as ProtobufSaveSessionResponse, ScrollDownInPaneIdPayload,
         ScrollToBottomInPaneIdPayload, ScrollToTopInPaneIdPayload, ScrollUpInPaneIdPayload,
         SetFloatingPanePinnedPayload, SetPaneBorderlessPayload, SetPaneColorPayload,
-        SetSelfMouseSelectionSupportPayload, SetTimeoutPayload, ShowCursorPayload,
-        ShowFloatingPanesPayload as ProtobufShowFloatingPanesPayload,
+        SetPaneRegexHighlightsPayload, SetSelfMouseSelectionSupportPayload, SetTimeoutPayload,
+        ShowCursorPayload, ShowFloatingPanesPayload as ProtobufShowFloatingPanesPayload,
         ShowFloatingPanesResponse as ProtobufShowFloatingPanesResponse, ShowPaneWithIdPayload,
         StackPanesPayload, SubscribePayload, SwitchSessionPayload, SwitchTabToIdPayload,
         SwitchTabToPayload, TogglePaneBorderlessPayload, TogglePaneEmbedOrEjectForPaneIdPayload,
@@ -118,8 +122,9 @@ pub use super::generated_api::api::{
 use crate::data::{
     ConnectToSession, DeleteLayoutResponse, EditLayoutResponse, FloatingPaneCoordinates,
     GetFocusedPaneInfoResponse, GetPaneCwdResponse, GetPanePidResponse,
-    GetPaneRunningCommandResponse, HttpVerb, InputMode, KeyWithModifier, MessageToPlugin,
-    NewPluginArgs, PaneId, PermissionType, PluginCommand, RenameLayoutResponse, SaveLayoutResponse,
+    GetPaneRunningCommandResponse, HighlightStyle, HttpVerb, InputMode, KeyWithModifier,
+    MessageToPlugin, NewPluginArgs, PaneId, PermissionType, PluginCommand, RegexHighlight,
+    RenameLayoutResponse, SaveLayoutResponse,
 };
 use crate::input::actions::Action;
 use crate::input::layout::PercentOrFixed;
@@ -2434,6 +2439,100 @@ impl TryFrom<ProtobufPluginCommand> for PluginCommand {
                 },
                 _ => Err("Mismatched payload for SetPaneColor"),
             },
+            Some(CommandName::SetPaneRegexHighlights) => {
+                match protobuf_plugin_command.payload {
+                    Some(Payload::SetPaneRegexHighlightsPayload(p)) => {
+                        let pane_id: PaneId = p
+                            .pane_id
+                            .ok_or("Missing pane_id in SetPaneRegexHighlights")?
+                            .try_into()?;
+                        let highlights = p
+                            .highlights
+                            .into_iter()
+                            .map(|h| {
+                                let style = match h.style.and_then(|s| s.style) {
+                                    Some(ProtobufHighlightStyleVariant::Emphasis0(_)) => {
+                                        HighlightStyle::Emphasis0
+                                    },
+                                    Some(ProtobufHighlightStyleVariant::Emphasis1(_)) => {
+                                        HighlightStyle::Emphasis1
+                                    },
+                                    Some(ProtobufHighlightStyleVariant::Emphasis2(_)) => {
+                                        HighlightStyle::Emphasis2
+                                    },
+                                    Some(ProtobufHighlightStyleVariant::Emphasis3(_)) => {
+                                        HighlightStyle::Emphasis3
+                                    },
+                                    Some(ProtobufHighlightStyleVariant::CustomRgb(c)) => {
+                                        HighlightStyle::CustomRgb {
+                                            fg: match (c.fg_r, c.fg_g, c.fg_b) {
+                                                (Some(r), Some(g), Some(b)) => {
+                                                    Some((r as u8, g as u8, b as u8))
+                                                },
+                                                _ => None,
+                                            },
+                                            bg: match (c.bg_r, c.bg_g, c.bg_b) {
+                                                (Some(r), Some(g), Some(b)) => {
+                                                    Some((r as u8, g as u8, b as u8))
+                                                },
+                                                _ => None,
+                                            },
+                                        }
+                                    },
+                                    Some(ProtobufHighlightStyleVariant::CustomIndex(c)) => {
+                                        HighlightStyle::CustomIndex {
+                                            fg: c.fg.map(|v| v as u8),
+                                            bg: c.bg.map(|v| v as u8),
+                                        }
+                                    },
+                                    Some(ProtobufHighlightStyleVariant::BackgroundEmphasis0(_)) => {
+                                        HighlightStyle::BackgroundEmphasis0
+                                    },
+                                    Some(ProtobufHighlightStyleVariant::BackgroundEmphasis1(_)) => {
+                                        HighlightStyle::BackgroundEmphasis1
+                                    },
+                                    Some(ProtobufHighlightStyleVariant::BackgroundEmphasis2(_)) => {
+                                        HighlightStyle::BackgroundEmphasis2
+                                    },
+                                    Some(ProtobufHighlightStyleVariant::BackgroundEmphasis3(_)) => {
+                                        HighlightStyle::BackgroundEmphasis3
+                                    },
+                                    Some(ProtobufHighlightStyleVariant::None(_)) => {
+                                        HighlightStyle::None
+                                    },
+                                    None => HighlightStyle::Emphasis0, // fallback
+                                };
+                                let context = h
+                                    .context
+                                    .into_iter()
+                                    .map(|item| (item.name, item.value))
+                                    .collect();
+                                RegexHighlight {
+                                    pattern: h.pattern,
+                                    style,
+                                    context,
+                                    on_hover: h.on_hover,
+                                    bold: h.bold,
+                                    italic: h.italic,
+                                    underline: h.underline,
+                                }
+                            })
+                            .collect();
+                        Ok(PluginCommand::SetPaneRegexHighlights(pane_id, highlights))
+                    },
+                    _ => Err("Mismatched payload for SetPaneRegexHighlights"),
+                }
+            },
+            Some(CommandName::ClearPaneHighlights) => match protobuf_plugin_command.payload {
+                Some(Payload::ClearPaneHighlightsPayload(p)) => {
+                    let pane_id: PaneId = p
+                        .pane_id
+                        .ok_or("Missing pane_id in ClearPaneHighlights")?
+                        .try_into()?;
+                    Ok(PluginCommand::ClearPaneHighlights(pane_id))
+                },
+                _ => Err("Mismatched payload for ClearPaneHighlights"),
+            },
             None => Err("Unrecognized plugin command"),
         }
     }
@@ -3994,6 +4093,93 @@ impl TryFrom<PluginCommand> for ProtobufPluginCommand {
                     bg,
                 })),
             }),
+            PluginCommand::SetPaneRegexHighlights(pane_id, highlights) => {
+                Ok(ProtobufPluginCommand {
+                    name: CommandName::SetPaneRegexHighlights as i32,
+                    payload: Some(Payload::SetPaneRegexHighlightsPayload(
+                        SetPaneRegexHighlightsPayload {
+                            pane_id: pane_id.try_into().ok(),
+                            highlights: highlights
+                                .into_iter()
+                                .map(|h| {
+                                    let style_variant = match h.style {
+                                        HighlightStyle::Emphasis0 => {
+                                            ProtobufHighlightStyleVariant::Emphasis0(true)
+                                        },
+                                        HighlightStyle::Emphasis1 => {
+                                            ProtobufHighlightStyleVariant::Emphasis1(true)
+                                        },
+                                        HighlightStyle::Emphasis2 => {
+                                            ProtobufHighlightStyleVariant::Emphasis2(true)
+                                        },
+                                        HighlightStyle::Emphasis3 => {
+                                            ProtobufHighlightStyleVariant::Emphasis3(true)
+                                        },
+                                        HighlightStyle::CustomRgb { fg, bg } => {
+                                            ProtobufHighlightStyleVariant::CustomRgb(
+                                                ProtobufCustomRgbHighlight {
+                                                    fg_r: fg.map(|(r, _, _)| r as u32),
+                                                    fg_g: fg.map(|(_, g, _)| g as u32),
+                                                    fg_b: fg.map(|(_, _, b)| b as u32),
+                                                    bg_r: bg.map(|(r, _, _)| r as u32),
+                                                    bg_g: bg.map(|(_, g, _)| g as u32),
+                                                    bg_b: bg.map(|(_, _, b)| b as u32),
+                                                },
+                                            )
+                                        },
+                                        HighlightStyle::CustomIndex { fg, bg } => {
+                                            ProtobufHighlightStyleVariant::CustomIndex(
+                                                ProtobufCustomIndexHighlight {
+                                                    fg: fg.map(|v| v as u32),
+                                                    bg: bg.map(|v| v as u32),
+                                                },
+                                            )
+                                        },
+                                        HighlightStyle::BackgroundEmphasis0 => {
+                                            ProtobufHighlightStyleVariant::BackgroundEmphasis0(true)
+                                        },
+                                        HighlightStyle::BackgroundEmphasis1 => {
+                                            ProtobufHighlightStyleVariant::BackgroundEmphasis1(true)
+                                        },
+                                        HighlightStyle::BackgroundEmphasis2 => {
+                                            ProtobufHighlightStyleVariant::BackgroundEmphasis2(true)
+                                        },
+                                        HighlightStyle::BackgroundEmphasis3 => {
+                                            ProtobufHighlightStyleVariant::BackgroundEmphasis3(true)
+                                        },
+                                        HighlightStyle::None => {
+                                            ProtobufHighlightStyleVariant::None(true)
+                                        },
+                                    };
+                                    ProtobufRegexHighlight {
+                                        pattern: h.pattern,
+                                        style: Some(ProtobufHighlightStyle {
+                                            style: Some(style_variant),
+                                        }),
+                                        context: h
+                                            .context
+                                            .into_iter()
+                                            .map(|(name, value)| ContextItem { name, value })
+                                            .collect(),
+                                        on_hover: h.on_hover,
+                                        bold: h.bold,
+                                        italic: h.italic,
+                                        underline: h.underline,
+                                    }
+                                })
+                                .collect(),
+                        },
+                    )),
+                })
+            },
+            PluginCommand::ClearPaneHighlights(pane_id) => Ok(ProtobufPluginCommand {
+                name: CommandName::ClearPaneHighlights as i32,
+                payload: Some(Payload::ClearPaneHighlightsPayload(
+                    ClearPaneHighlightsPayload {
+                        pane_id: pane_id.try_into().ok(),
+                    },
+                )),
+            }),
         }
     }
 }