Add start_separator

[lorber13]

Linked to issue #2066

[bim9262]

@siddarth2810 raises a good point on the issue, the color for the start separator should match the first segment of the first block.

Something like...

diff --git a/src/protocol.rs b/src/protocol.rs
index df6007ff0..5ee8877b1 100644
--- a/src/protocol.rs
+++ b/src/protocol.rs
@@ -25,11 +25,17 @@ where
     let mut prev_last_bg = Color::None;
     let mut rendered_blocks = vec![];
 
-    // The right most block should never be alternated
-    let mut alt = blocks
+    let blocks_with_segments: Vec<RenderedBlock> = blocks
         .iter()
         .map(|x| x.borrow())
-        .filter(|x| !x.segments.is_empty() && !x.merge_with_next)
+        .filter(|x| !x.segments.is_empty())
+        .cloned()
+        .collect();
+
+    // The right most block should never be alternated
+    let mut alt = blocks_with_segments
+        .iter()
+        .filter(|x| !x.merge_with_next)
         .count()
         % 2
         == 0;
@@ -42,17 +48,21 @@ where
         rendered_blocks.push(I3BarBlock {
             full_text: start_separator.clone(),
             background: Color::None,
-            color: prev_last_bg,
+            // Peek at the first segment of the first first block to see what color it is
+            color: blocks_with_segments.first().map_or(Color::None, |widget| {
+                widget.segments.first().map_or(Color::None, |segment| {
+                    if alt {
+                        segment.background + config.theme.alternating_tint_bg
+                    } else {
+                        segment.background
+                    }
+                })
+            }),
             ..Default::default()
         });
     }
 
-    for widgets in blocks
-        .iter()
-        .map(|x| x.borrow())
-        .filter(|x| !x.segments.is_empty())
-        .cloned()
-    {
+    for widgets in blocks_with_segments {
         let RenderedBlock {
             mut segments,
             merge_with_next,

[bim9262]

Both your code and what I wrote yesterday don't replace the first separator, but just add another in front, but perhaps it would be better to replace it with the specified separator like

<start separator, if set, else separator><block 1><separator><block 2>...<end separator, if set>

Perhaps

diff --git a/src/protocol.rs b/src/protocol.rs
index df6007ff0..72e774701 100644
--- a/src/protocol.rs
+++ b/src/protocol.rs
@@ -38,20 +38,12 @@ where
 
     let mut prev_merge_with_next = false;
 
-    if let Separator::Custom(start_separator) = &config.theme.start_separator {
-        rendered_blocks.push(I3BarBlock {
-            full_text: start_separator.clone(),
-            background: Color::None,
-            color: prev_last_bg,
-            ..Default::default()
-        });
-    }
-
-    for widgets in blocks
+    for (i, widgets) in blocks
         .iter()
         .map(|x| x.borrow())
         .filter(|x| !x.segments.is_empty())
         .cloned()
+        .enumerate()
     {
         let RenderedBlock {
             mut segments,
@@ -73,7 +65,12 @@ where
             alt = !alt;
         }
 
-        if let Separator::Custom(separator) = &config.theme.separator {
+        let separator = match &config.theme.start_separator {
+            Separator::Custom(_) if i == 0 => &config.theme.start_separator,
+            _ => &config.theme.separator,
+        };
+
+        if let Separator::Custom(separator) = separator {
             if !prev_merge_with_next {
                 // The first widget's BG is used to get the FG color for the current separator
                 let sep_fg = if config.theme.separator_fg == Color::Auto {

[siddarth2810]

wow so if i am not wrong block_with_segments part was creating an extra theme separator at the start, so you used i=0 to check if its first block and only use start separator for that. So cool

If its alright, I can take this up :)

[lorber13]

Both your code and what I wrote yesterday don't replace the first separator, but just add another in front, but perhaps it would be better to replace it with the specified separator like

<start separator, if set, else separator><block 1><separator><block 2>...<end separator, if set>
Perhaps

diff --git a/src/protocol.rs b/src/protocol.rs
index df6007ff0..72e774701 100644
--- a/src/protocol.rs
+++ b/src/protocol.rs
@@ -38,20 +38,12 @@ where
 
     let mut prev_merge_with_next = false;
 
-    if let Separator::Custom(start_separator) = &config.theme.start_separator {
-        rendered_blocks.push(I3BarBlock {
-            full_text: start_separator.clone(),
-            background: Color::None,
-            color: prev_last_bg,
-            ..Default::default()
-        });
-    }
-
-    for widgets in blocks
+    for (i, widgets) in blocks
         .iter()
         .map(|x| x.borrow())
         .filter(|x| !x.segments.is_empty())
         .cloned()
+        .enumerate()
     {
         let RenderedBlock {
             mut segments,
@@ -73,7 +65,12 @@ where
             alt = !alt;
         }
 
-        if let Separator::Custom(separator) = &config.theme.separator {
+        let separator = match &config.theme.start_separator {
+            Separator::Custom(_) if i == 0 => &config.theme.start_separator,
+            _ => &config.theme.separator,
+        };
+
+        if let Separator::Custom(separator) = separator {
             if !prev_merge_with_next {
                 // The first widget's BG is used to get the FG color for the current separator
                 let sep_fg = if config.theme.separator_fg == Color::Auto {

Why do we need a start separator if the default separator is already present before the first block? I'm starting to have doubts about its usefulness.
EDIT: after reading again the issue description, it seems that the behavior we want is the ability to replace the first separator. Sorry, I misunderstood.

[MaxVerevkin]

Does not currently work as expected, please apply @bim9262's suggestion.