Merge branch 'tab-layout' of https://github.com/a-kenji/zellij into a-kenji-tab-layout

11 files changed, 1241 insertions, 26 deletions

diff --git a/zellij-utils/src/input/actions.rs b/zellij-utils/src/input/actions.rs
index 23c01eefe..cd4ca4641 100644
--- a/zellij-utils/src/input/actions.rs
+++ b/zellij-utils/src/input/actions.rs
@@ -1,6 +1,7 @@
 //! Definition of the actions that can be bound to keys.
 
 use super::command::RunCommandAction;
+use super::layout::TabLayout;
 use crate::input::options::OnForceClose;
 use serde::{Deserialize, Serialize};
 use zellij_tile::data::InputMode;
@@ -19,7 +20,7 @@ pub enum Direction {
 // As these actions are bound to the default config, please
 // do take care when refactoring - or renaming.
 // They might need to be adjusted in the default config
-// as well `../../../assets/config/default.yaml`
+// as well `../../assets/config/default.yaml`
 /// Actions that can be bound to keys.
 #[derive(Eq, Clone, Debug, PartialEq, Deserialize, Serialize)]
 pub enum Action {
@@ -65,8 +66,8 @@ pub enum Action {
     NewPane(Option<Direction>),
     /// Close the focus pane.
     CloseFocus,
-    /// Create a new tab.
-    NewTab,
+    /// Create a new tab, optionally with a specified tab layout.
+    NewTab(Option<TabLayout>),
     /// Do nothing.
     NoOp,
     /// Go to the next tab.
diff --git a/zellij-utils/src/input/config.rs b/zellij-utils/src/input/config.rs
index 6a65109a7..930fe07af 100644
--- a/zellij-utils/src/input/config.rs
+++ b/zellij-utils/src/input/config.rs
@@ -45,6 +45,9 @@ pub enum ConfigError {
     IoPath(io::Error, PathBuf),
     // Internal Deserialization Error
     FromUtf8(std::string::FromUtf8Error),
+    // Missing the tab section in the layout.
+    Layout(LayoutMissingTabSectionError),
+    LayoutPartAndTab(LayoutPartAndTabError),
 }
 
 impl Default for Config {
@@ -129,6 +132,75 @@ impl Config {
     }
 }
 
+// TODO: Split errors up into separate modules
+#[derive(Debug, Clone)]
+pub struct LayoutMissingTabSectionError;
+#[derive(Debug, Clone)]
+pub struct LayoutPartAndTabError;
+
+impl fmt::Display for LayoutMissingTabSectionError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(
+            f,
+            "MissingTabSectionError:
+There needs to be exactly one `tabs` section specified in the layout file, for example:
+---
+direction: Horizontal
+parts:
+  - direction: Vertical
+  - direction: Vertical
+    tabs:
+      - direction: Vertical
+      - direction: Vertical
+  - direction: Vertical
+"
+        )
+    }
+}
+
+impl std::error::Error for LayoutMissingTabSectionError {
+    fn description(&self) -> &str {
+        "One tab must be specified per Layout."
+    }
+}
+
+impl fmt::Display for LayoutPartAndTabError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(
+            f,
+            "LayoutPartAndTabError:
+The `tabs` and `parts` section should not be specified on the same level in the layout file, for example:
+---
+direction: Horizontal
+parts:
+  - direction: Vertical
+  - direction: Vertical
+tabs:
+  - direction: Vertical
+  - direction: Vertical
+  - direction: Vertical
+
+should rather be specified as:
+---
+direction: Horizontal
+parts:
+  - direction: Vertical
+  - direction: Vertical
+    tabs:
+      - direction: Vertical
+      - direction: Vertical
+      - direction: Vertical
+"
+        )
+    }
+}
+
+impl std::error::Error for LayoutPartAndTabError {
+    fn description(&self) -> &str {
+        "The `tabs` and parts section should not be specified on the same level."
+    }
+}
+
 impl Display for ConfigError {
     fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
         match self {
@@ -138,6 +210,12 @@ impl Display for ConfigError {
             }
             ConfigError::Serde(ref err) => write!(formatter, "Deserialization error: {}", err),
             ConfigError::FromUtf8(ref err) => write!(formatter, "FromUtf8Error: {}", err),
+            ConfigError::Layout(ref err) => {
+                write!(formatter, "There was an error in the layout file, {}", err)
+            }
+            ConfigError::LayoutPartAndTab(ref err) => {
+                write!(formatter, "There was an error in the layout file, {}", err)
+            }
         }
     }
 }
@@ -149,6 +227,8 @@ impl std::error::Error for ConfigError {
             ConfigError::IoPath(ref err, _) => Some(err),
             ConfigError::Serde(ref err) => Some(err),
             ConfigError::FromUtf8(ref err) => Some(err),
+            ConfigError::Layout(ref err) => Some(err),
+            ConfigError::LayoutPartAndTab(ref err) => Some(err),
         }
     }
 }
@@ -171,6 +251,18 @@ impl From<std::string::FromUtf8Error> for ConfigError {
     }
 }
 
+impl From<LayoutMissingTabSectionError> for ConfigError {
+    fn from(err: LayoutMissingTabSectionError) -> ConfigError {
+        ConfigError::Layout(err)
+    }
+}
+
+impl From<LayoutPartAndTabError> for ConfigError {
+    fn from(err: LayoutPartAndTabError) -> ConfigError {
+        ConfigError::LayoutPartAndTab(err)
+    }
+}
+
 // The unit test location.
 #[cfg(test)]
 mod config_test {
diff --git a/zellij-utils/src/input/layout.rs b/zellij-utils/src/input/layout.rs
index 33e08bfdb..96f6189c9 100644
--- a/zellij-utils/src/input/layout.rs
+++ b/zellij-utils/src/input/layout.rs
@@ -17,23 +17,26 @@ use crate::{serde, serde_yaml};
 
 use serde::{Deserialize, Serialize};
 use std::path::{Path, PathBuf};
+use std::vec::Vec;
 use std::{fs::File, io::prelude::*};
 
-#[derive(Debug, Serialize, Deserialize, Clone)]
+use super::config::{LayoutMissingTabSectionError, LayoutPartAndTabError};
+
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
 #[serde(crate = "self::serde")]
 pub enum Direction {
     Horizontal,
     Vertical,
 }
 
-#[derive(Debug, Serialize, Deserialize, Clone, Copy)]
+#[derive(Debug, Serialize, Deserialize, Clone, Copy, PartialEq, Eq)]
 #[serde(crate = "self::serde")]
 pub enum SplitSize {
     Percent(u8), // 1 to 100
     Fixed(u16),  // An absolute number of columns or rows
 }
 
-#[derive(Debug, Serialize, Deserialize, Clone)]
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
 #[serde(crate = "self::serde")]
 pub enum Run {
     #[serde(rename = "plugin")]
@@ -42,35 +45,49 @@ pub enum Run {
     Command(RunCommand),
 }
 
-#[derive(Debug, Serialize, Deserialize, Clone)]
+// The layout struct ultimately used to build the layouts.
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
 #[serde(crate = "self::serde")]
 pub struct Layout {
     pub direction: Direction,
     #[serde(default)]
     pub parts: Vec<Layout>,
+    #[serde(default)]
+    pub tabs: Vec<TabLayout>,
     pub split_size: Option<SplitSize>,
     pub run: Option<Run>,
     #[serde(default)]
     pub borderless: bool,
 }
 
-type LayoutResult = Result<Layout, ConfigError>;
+// The struct that is used to deserialize the layout from
+// a yaml configuration file
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
+#[serde(crate = "self::serde")]
+pub struct LayoutFromYaml {
+    //#[serde(default)]
+    pub template: LayoutTemplateFromYaml,
+    #[serde(default)]
+    pub tabs: Vec<TabLayout>,
+}
 
-impl Layout {
-    pub fn new(layout_path: &Path) -> LayoutResult {
+type LayoutFromYamlResult = Result<LayoutFromYaml, ConfigError>;
+
+impl LayoutFromYaml {
+    pub fn new(layout_path: &Path) -> LayoutFromYamlResult {
         let mut layout_file = File::open(&layout_path)
             .or_else(|_| File::open(&layout_path.with_extension("yaml")))
             .map_err(|e| ConfigError::IoPath(e, layout_path.into()))?;
 
         let mut layout = String::new();
         layout_file.read_to_string(&mut layout)?;
-        let layout: Layout = serde_yaml::from_str(&layout)?;
+        let layout: LayoutFromYaml = serde_yaml::from_str(&layout)?;
         Ok(layout)
     }
 
     // It wants to use Path here, but that doesn't compile.
     #[allow(clippy::ptr_arg)]
-    pub fn from_dir(layout: &PathBuf, layout_dir: Option<&PathBuf>) -> LayoutResult {
+    pub fn from_dir(layout: &PathBuf, layout_dir: Option<&PathBuf>) -> LayoutFromYamlResult {
         match layout_dir {
             Some(dir) => Self::new(&dir.join(layout))
                 .or_else(|_| Self::from_default_assets(layout.as_path())),
@@ -82,22 +99,31 @@ impl Layout {
         layout: Option<&PathBuf>,
         layout_path: Option<&PathBuf>,
         layout_dir: Option<PathBuf>,
-    ) -> Option<Result<Layout, ConfigError>> {
+    ) -> Option<LayoutFromYamlResult> {
         layout
-            .map(|p| Layout::from_dir(p, layout_dir.as_ref()))
-            .or_else(|| layout_path.map(|p| Layout::new(p)))
+            .map(|p| LayoutFromYaml::from_dir(p, layout_dir.as_ref()))
+            .or_else(|| layout_path.map(|p| LayoutFromYaml::new(p)))
             .or_else(|| {
-                Some(Layout::from_dir(
+                Some(LayoutFromYaml::from_dir(
                     &std::path::PathBuf::from("default"),
                     layout_dir.as_ref(),
                 ))
             })
     }
 
+    pub fn construct_layout_template(&self) -> LayoutTemplate {
+        let (pre_tab, post_tab) = self.template.split_template().unwrap();
+        LayoutTemplate {
+            pre_tab: pre_tab.into(),
+            post_tab: Layout::from_vec_template_layout(post_tab),
+            tabs: self.tabs.clone(),
+        }
+    }
+
     // Currently still needed but on nightly
     // this is already possible:
     // HashMap<&'static str, Vec<u8>>
-    pub fn from_default_assets(path: &Path) -> LayoutResult {
+    pub fn from_default_assets(path: &Path) -> LayoutFromYamlResult {
         match path.to_str() {
             Some("default") => Self::default_from_assets(),
             Some("strider") => Self::strider_from_assets(),
@@ -111,24 +137,123 @@ impl Layout {
 
     // TODO Deserialize the assets from bytes &[u8],
     // once serde-yaml supports zero-copy
-    pub fn default_from_assets() -> LayoutResult {
-        let layout: Layout =
+    pub fn default_from_assets() -> LayoutFromYamlResult {
+        let layout: LayoutFromYaml =
             serde_yaml::from_str(String::from_utf8(setup::DEFAULT_LAYOUT.to_vec())?.as_str())?;
         Ok(layout)
     }
 
-    pub fn strider_from_assets() -> LayoutResult {
-        let layout: Layout =
+    pub fn strider_from_assets() -> LayoutFromYamlResult {
+        let layout: LayoutFromYaml =
             serde_yaml::from_str(String::from_utf8(setup::STRIDER_LAYOUT.to_vec())?.as_str())?;
         Ok(layout)
     }
 
-    pub fn disable_status_from_assets() -> LayoutResult {
-        let layout: Layout =
+    pub fn disable_status_from_assets() -> LayoutFromYamlResult {
+        let layout: LayoutFromYaml =
             serde_yaml::from_str(String::from_utf8(setup::NO_STATUS_LAYOUT.to_vec())?.as_str())?;
         Ok(layout)
     }
+}
+
+// The struct that carries the information template that is used to
+// construct the layout
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
+#[serde(crate = "self::serde")]
+pub struct LayoutTemplateFromYaml {
+    pub direction: Direction,
+    #[serde(default)]
+    pub parts: Vec<LayoutTemplateFromYaml>,
+    #[serde(default)]
+    pub body: bool,
+    pub split_size: Option<SplitSize>,
+    pub run: Option<Run>,
+}
+
+impl LayoutTemplateFromYaml {
+    // Split the layout into parts that can be reassebled per tab
+    // returns the layout pre tab and the parts post tab
+    pub fn split_template(
+        &self,
+    ) -> Result<(LayoutTemplateFromYaml, Vec<LayoutTemplateFromYaml>), LayoutPartAndTabError> {
+        let mut main_layout = self.clone();
+        let mut pre_tab_layout = self.clone();
+        let mut post_tab_layout = vec![];
+        let mut post_tab = false;
+
+        pre_tab_layout.parts.clear();
+
+        if main_layout.body {
+            post_tab = true;
+        }
+
+        for part in main_layout.parts.drain(..) {
+            let (curr_pre_layout, mut curr_post_layout) = part.split_template()?;
+
+            // Leaf
+            if !post_tab && !part.body {
+                pre_tab_layout.parts.push(curr_pre_layout);
+            }
+
+            // Node
+            if part.body {
+                post_tab = true;
+            // Leaf
+            } else if post_tab {
+                if curr_post_layout.is_empty() {
+                    let mut part_no_tab = part.clone();
+                    part_no_tab.parts.clear();
+                    post_tab_layout.push(part_no_tab);
+                } else {
+                    post_tab_layout.append(&mut curr_post_layout);
+                }
+            }
+        }
+        Ok((pre_tab_layout, post_tab_layout))
+    }
+}
+
+// The tab-layout struct used to specify each individual tab.
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
+#[serde(crate = "self::serde")]
+pub struct TabLayout {
+    pub direction: Direction,
+    #[serde(default)]
+    pub parts: Vec<TabLayout>,
+    pub split_size: Option<SplitSize>,
+    pub run: Option<Run>,
+}
+
+// Main template layout struct, that carries information based on position of
+// tabs in relation to the whole layout.
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
+#[serde(crate = "self::serde")]
+pub struct LayoutTemplate {
+    pub pre_tab: Layout,
+    pub post_tab: Vec<Layout>,
+    pub tabs: Vec<TabLayout>,
+}
+
+impl LayoutTemplate {
+    pub fn construct_tab_layout(&self, tab_layout: Option<TabLayout>) -> Layout {
+        if let Some(tab_layout) = tab_layout {
+            let mut pre_tab_layout = self.pre_tab.clone();
+            let post_tab_layout = &self.post_tab;
+            pre_tab_layout.merge_tab_layout(tab_layout);
+            pre_tab_layout.merge_layout_parts(post_tab_layout.to_owned());
+            pre_tab_layout
+        } else {
+            let mut pre_tab_layout = self.pre_tab.clone();
+            let post_tab_layout = &self.post_tab;
+            let default_tab_layout = TabLayout::default();
+            pre_tab_layout.merge_tab_layout(default_tab_layout);
+            pre_tab_layout.merge_layout_parts(post_tab_layout.to_owned());
+            pre_tab_layout
+        }
+    }
+}
 
+impl Layout {
     pub fn total_terminal_panes(&self) -> usize {
         let mut total_panes = 0;
         total_panes += self.parts.len();
@@ -169,6 +294,101 @@ impl Layout {
     ) -> Vec<(Layout, PositionAndSize)> {
         split_space(space, self)
     }
+
+    // Split the layout into parts that can be reassebled per tab
+    // returns the layout pre tab, the parts post tab and the tab layouts
+    pub fn split_main_and_tab_layout(
+        &self,
+    ) -> Result<(Layout, Vec<Layout>, Vec<TabLayout>), LayoutPartAndTabError> {
+        let mut main_layout = self.clone();
+        let mut pre_tab_layout = self.clone();
+        let mut post_tab_layout = vec![];
+        let mut tabs = vec![];
+        let mut post_tab = false;
+
+        pre_tab_layout.parts.clear();
+        pre_tab_layout.tabs.clear();
+
+        if !main_layout.tabs.is_empty() {
+            tabs.append(&mut main_layout.tabs);
+            post_tab = true;
+        }
+
+        if !main_layout.tabs.is_empty() && !main_layout.parts.is_empty() {
+            return Err(LayoutPartAndTabError);
+        }
+
+        for part in main_layout.parts.drain(..) {
+            let (curr_pre_layout, mut curr_post_layout, mut curr_tabs) =
+                part.split_main_and_tab_layout()?;
+
+            // Leaf
+            if !post_tab && part.tabs.is_empty() {
+                pre_tab_layout.parts.push(curr_pre_layout);
+            }
+
+            if !part.tabs.is_empty() && !part.parts.is_empty() {
+                return Err(LayoutPartAndTabError);
+            }
+
+            // Node
+            if !part.tabs.is_empty() {
+                tabs.append(&mut part.tabs.clone());
+                post_tab = true;
+            // Node
+            } else if !curr_tabs.is_empty() {
+                tabs.append(&mut curr_tabs);
+                post_tab = true;
+            // Leaf
+            } else if post_tab {
+                if curr_post_layout.is_empty() {
+                    let mut part_no_tab = part.clone();
+                    part_no_tab.tabs.clear();
+                    part_no_tab.parts.clear();
+                    post_tab_layout.push(part_no_tab);
+                } else {
+                    post_tab_layout.append(&mut curr_post_layout);
+                }
+            }
+        }
+        Ok((pre_tab_layout, post_tab_layout, tabs))
+    }
+
+    pub fn merge_tab_layout(&mut self, tab: TabLayout) {
+        self.parts.push(tab.into());
+    }
+
+    pub fn merge_layout_parts(&mut self, mut parts: Vec<Layout>) {
+        self.parts.append(&mut parts);
+    }
+
+    pub fn construct_layout_template(&self) -> Result<LayoutTemplate, ConfigError> {
+        let (pre_tab, post_tab, tabs) = self.split_main_and_tab_layout()?;
+
+        if tabs.is_empty() {
+            return Err(ConfigError::Layout(LayoutMissingTabSectionError));
+        }
+
+        Ok(LayoutTemplate {
+            pre_tab,
+            post_tab,
+            tabs,
+        })
+    }
+
+    fn from_vec_tab_layout(tab_layout: Vec<TabLayout>) -> Vec<Self> {
+        tab_layout
+            .iter()
+            .map(|tab_layout| Layout::from(tab_layout.to_owned()))
+            .collect()
+    }
+
+    fn from_vec_template_layout(layout_template: Vec<LayoutTemplateFromYaml>) -> Vec<Self> {
+        layout_template
+            .iter()
+            .map(|layout_template| Layout::from(layout_template.to_owned()))
+            .collect()
+    }
 }
 
 fn split_space_to_parts_vertically(
@@ -323,3 +543,43 @@ fn split_space(
     }
     pane_positions
 }
+
+impl From<TabLayout> for Layout {
+    fn from(tab: TabLayout) -> Self {
+        Layout {
+            direction: tab.direction,
+            parts: Layout::from_vec_tab_layout(tab.parts),
+            tabs: vec![],
+            split_size: tab.split_size,
+            run: tab.run,
+        }
+    }
+}
+
+impl From<LayoutTemplateFromYaml> for Layout {
+    fn from(template: LayoutTemplateFromYaml) -> Self {
+        Layout {
+            direction: template.direction,
+            parts: Layout::from_vec_template_layout(template.parts),
+            tabs: vec![],
+            split_size: template.split_size,
+            run: template.run,
+        }
+    }
+}
+
+impl Default for TabLayout {
+    fn default() -> Self {
+        Self {
+            direction: Direction::Horizontal,
+            parts: vec![],
+            split_size: None,
+            run: None,
+        }
+    }
+}
+
+// The unit test location.
+#[cfg(test)]
+#[path = "./unit/layout_test.rs"]
+mod layout_test;
diff --git a/zellij-utils/src/input/unit/fixtures/layouts/deeply-nested-tab-layout.yaml b/zellij-utils/src/input/unit/fixtures/layouts/deeply-nested-tab-layout.yaml
new file mode 100644
index 000000000..633a1fae2
--- /dev/null
+++ b/zellij-utils/src/input/unit/fixtures/layouts/deeply-nested-tab-layout.yaml
@@ -0,0 +1,43 @@
+---
+template:
+  direction: Horizontal
+  parts:
+    - direction: Vertical
+      parts:
+        - direction: Horizontal
+          split_size:
+            Percent: 21
+        - direction: Vertical
+          split_size:
+            Percent: 79
+          parts:
+            - direction: Horizontal
+              split_size:
+                Percent: 22
+            - direction: Horizontal
+              split_size:
+                Percent: 78
+              parts:
+                - direction: Horizontal
+                  split_size:
+                    Percent: 23
+                - direction: Vertical
+                  split_size:
+                    Percent: 77
+                  body: true
+      split_size:
+        Percent: 90
+    - direction: Vertical
+      split_size:
+        Percent: 15
+    - direction: Vertical
+      split_size:
+        Percent: 15
+    - direction: Vertical
+      split_size:
+        Percent: 15
+
+tabs:
+  - direction: Horizontal
+    split_size:
+      Percent: 24
diff --git a/zellij-utils/src/input/unit/fixtures/layouts/multiple-tabs-should-not-error.yaml b/zellij-utils/src/input/unit/fixtures/layouts/multiple-tabs-should-not-error.yaml
new file mode 100644
index 000000000..653787591
--- /dev/null
+++ b/zellij-utils/src/input/unit/fixtures/layouts/multiple-tabs-should-not-error.yaml
@@ -0,0 +1,18 @@
+---
+direction: Horizontal
+parts:
+  - direction: Horizontal
+    parts:
+      - direction: Vertical
+        parts:
+          - direction: Horizontal
+            split_size:
+              Percent: 50
+          - direction: Horizontal
+            tabs:
+              - direction: Vertical
+                split_size:
+                  Percent: 50
+              - direction: Vertical
+                split_size:
+                  Percent: 50
diff --git a/zellij-utils/src/input/unit/fixtures/layouts/three-panes-with-tab-and-command.yaml b/zellij-utils/src/input/unit/fixtures/layouts/three-panes-with-tab-and-command.yaml
new file mode 100644
index 000000000..9ad1034d4
--- /dev/null
+++ b/zellij-utils/src/input/unit/fixtures/layouts/three-panes-with-tab-and-command.yaml
@@ -0,0 +1,35 @@
+---
+template:
+  direction: Horizontal
+  parts:
+    - direction: Vertical
+      split_size:
+        Fixed: 1
+      run:
+        plugin: tab-bar
+    - direction: Horizontal
+      body: true
+    - direction: Vertical
+      split_size:
+        Fixed: 2
+      run:
+        plugin: status-bar
+
+tabs:
+  - direction: Vertical
+    parts:
+      - direction: Horizontal
+        split_size: