feat: allow aligning content inside breakpoints and threads (#129)

Author: igorlfs

docs/src/routes/configuration/+page.md

@@ -11,7 +11,7 @@ The default configuration below is applied when the plugin is _loaded_ (**no `se
 These are the default options for `nvim-dap-view`.
 
 :::note
-You don't have to copy and paste these options. Use them as a reference.
+**You don't have to copy and paste these options.** Use them as a reference.
 :::
 
 ```lua
@@ -115,6 +115,32 @@ return {
         -- Optionally a function that takes two `dap.Variable`'s as arguments
         -- and is forwarded to a `table.sort` when rendering variables in the scopes view
         sort_variables = nil,
+        -- Full control of how frames are rendered, see the "Custom Formatting" page
+        threads = {
+            -- Choose which items to display and how
+            format = function(name, lnum, path)
+                return {
+                    { part = name, separator = " " },
+                    { part = path, hl = "FileName", separator = ":" },
+                    { part = lnum, hl = "LineNumber" },
+                }
+            end,
+            -- Align columns
+            align = false,
+        },
+        -- Full control of how breakpoints are rendered, see the "Custom Formatting" page
+        breakpoints = {
+            -- Choose which items to display and how
+            format = function(line, lnum, path)
+                return {
+                    { part = path, hl = "FileName" },
+                    { part = lnum, hl = "LineNumber" },
+                    { part = line, hl = true },
+                }
+            end,
+            -- Align columns
+            align = false,
+        },
     },
     -- Controls how to jump when selecting a breakpoint or navigating the stack
     -- Comma separated list, like the built-in 'switchbuf'. See :help 'switchbuf'

docs/src/routes/custom-formatting/+page.md

@@ -5,6 +5,10 @@ category: Recipes
 
 You can control how the text is displayed for some views, using special `format` functions. Each customizable view has its own parameters, but the expected return type is the same: an array of `{part: string, hl?: string, separator?: string}`. The `part` is the "content" itself, `hl` is one of `nvim-dap-view`'s [highlight groups](./highlight-groups) (without the `NvimDapView` prefix) and the separator can be used to customize the divider between the current part and the next one.
 
+The separator must be a single character. A pipe (`|`) is used if not specified.
+
+Additionally, both `threads` and `breakpoints` support a flag for aligning their columns.
+
 ## Threads
 
 You can manipulate the frame _name_ (usually the function name), its line number and path.
@@ -65,6 +69,8 @@ return {
                     { part = line, hl = true },
                 }
             end,
+            -- Alignment enjoyer
+            align = true,
         },
     },
 }

lua/dap-view/breakpoints/view.lua

@@ -35,6 +35,11 @@ M.show = function()
             state.breakpoint_lines_by_line[i] = nil
         end
 
+        ---@type integer[][]
+        local lengths = {}
+
+        local num_parts = 0
+
         for buf, buf_entries in pairs(breakpoints) do
             local filename = api.nvim_buf_get_name(buf)
             local relative_path = vim.fn.fnamemodify(filename, ":.")
@@ -45,6 +50,21 @@ M.show = function()
 
                 local parts = setup.config.render.breakpoints.format(text, tostring(entry.lnum), relative_path)
 
+                for _, p in ipairs(parts) do
+                    assert(not p.separator or #p.separator == 1, "Separator length must not exceeed 1 character")
+                end
+
+                num_parts = #parts - 1
+
+                lengths[#lengths + 1] = vim.iter(parts)
+                    :map(
+                        ---@param part dapview.Content
+                        function(part)
+                            return #part.part
+                        end
+                    )
+                    :totable()
+
                 table.insert(state.breakpoint_paths_by_line, relative_path)
                 table.insert(state.breakpoint_lines_by_line, entry.lnum)
 
@@ -81,6 +101,10 @@ M.show = function()
             end
         end
 
+        if setup.config.render.breakpoints.align then
+            require("dap-view.util.align").align(num_parts, lengths)
+        end
+
         -- Clear previous content
         util.set_lines(state.bufnr, line, -1, true, {})
     end

lua/dap-view/config.lua

@@ -75,9 +75,11 @@ local M = {}
 
 ---@class dapview.RenderBreakpointsConfig
 ---@field format fun(line: string, lnum: string, path: string): dapview.Content[]
+---@field align boolean
 
 ---@class dapview.RenderThreadsConfig
 ---@field format fun(name: string, lnum: string, path: string): dapview.Content[]
+---@field align boolean
 
 ---@class dapview.RenderConfig
 ---@field sort_variables? fun(lhs: dap.Variable, rhs: dap.Variable): boolean Override order of variables
@@ -189,6 +191,7 @@ M.config = {
     render = {
         sort_variables = nil,
         threads = {
+            align = false,
             format = function(name, lnum, path)
                 return {
                     { part = name, separator = " " },
@@ -198,6 +201,7 @@ M.config = {
             end,
         },
         breakpoints = {
+            align = false,
             format = function(line, lnum, path)
                 return {
                     { part = path, hl = "FileName" },

lua/dap-view/setup/validate/render.lua

@@ -13,11 +13,13 @@ function M.validate(config)
     local threads = config.threads
     validate("render.threads", {
         format = { threads.format, { "function" } },
+        align = { threads.align, { "boolean" } },
     }, threads)
 
     local breakpoints = config.breakpoints
     validate("render.breakpoints", {
         format = { breakpoints.format, { "function" } },
+        align = { breakpoints.align, { "boolean" } },
     }, breakpoints)
 end
 

lua/dap-view/threads/view.lua

@@ -83,7 +83,19 @@ M.show = function()
 
         local has_no_filter = state.threads_filter == ""
 
+        ---@type integer[][]
+        local lengths = {}
+
+        local num_parts = 0
+
+        ---@type integer[]
+        local row_offsets = {}
+
+        local row_offset = 0
+
         for k, thread in pairs(session.threads) do
+            row_offset = row_offset + 1
+
             local is_stopped_thread = session.stopped_thread_id == thread.id
             local thread_name = is_stopped_thread and thread.name .. " " .. config.icons["pause"] or thread.name
             util.set_lines(state.bufnr, line, line, true, { thread_name })
@@ -137,16 +149,37 @@ M.show = function()
                     end
                 )
 
-                local formated_frames = vim.iter(frames):map(
+                local formatted_frames = vim.iter(frames):map(
                     ---@param frame dapview.Frame
                     function(frame)
                         local format = config.render.threads.format(frame.name, frame.lnum, frame.path)
+
+                        for _, p in ipairs(format) do
+                            assert(
+                                not p.separator or #p.separator == 1,
+                                "Separator length must not exceeed 1 character"
+                            )
+                        end
+
+                        num_parts = #format - 1
+
+                        lengths[#lengths + 1] = vim.iter(format)
+                            :map(
+                                ---@param part dapview.Content
+                                function(part)
+                                    return #part.part
+                                end
+                            )
+                            :totable()
+
+                        row_offsets[#row_offsets + 1] = row_offset
+
                         return { content = format, id = frame.id }
                     end
                 )
 
                 ---@type dapview.FrameContent[]
-                local filtered_frames = formated_frames
+                local filtered_frames = formatted_frames
                     :filter(
                         ---@param f dapview.FrameContent
                         function(f)
@@ -217,6 +250,10 @@ M.show = function()
             end
         end
 
+        if setup.config.render.breakpoints.align then
+            require("dap-view.util.align").align(num_parts, lengths, 1, row_offsets)
+        end
+
         -- Clear previous content
         util.set_lines(state.bufnr, line, -1, true, {})
     end

lua/dap-view/util/align.lua

@@ -0,0 +1,64 @@
+local globals = require("dap-view.globals")
+local state = require("dap-view.state")
+
+local M = {}
+
+local api = vim.api
+
+---@param num_parts integer
+---@param lengths integer[][]
+---@param col_offset? integer
+---@param row_offsets? integer[]
+M.align = function(num_parts, lengths, col_offset, row_offsets)
+    col_offset = col_offset or 0
+    row_offsets = row_offsets or {}
+
+    ---@type integer[]
+    local maxes = {}
+    ---@type integer[][]
+    local diffs = {}
+
+    for _ = 1, num_parts do
+        maxes[#maxes + 1] = 0
+    end
+
+    for i = 1, num_parts do
+        for j = 1, #lengths do
+            diffs[#diffs + 1] = {}
+            if lengths[j][i] > maxes[i] then
+                maxes[i] = lengths[j][i]
+            end
+        end
+    end
+
+    for i = 1, num_parts do
+        for j = 1, #lengths do
+            diffs[j][i] = maxes[i] - lengths[j][i]
+        end
+    end
+
+    for i, k in ipairs(diffs) do
+        local cur_col = col_offset
+
+        for j, v in ipairs(k) do
+            local row = i - 1
+            if row_offsets[i] then
+                row = row + row_offsets[i]
+            end
+
+            local col = lengths[i][j] + cur_col
+
+            -- Account for the separator
+            cur_col = col + 1
+
+            if v > 0 then
+                api.nvim_buf_set_extmark(state.bufnr, globals.NAMESPACE, row, col, {
+                    virt_text = { { string.rep(" ", v) } },
+                    virt_text_pos = "inline",
+                })
+            end
+        end
+    end
+end
+
+return M

lua/dap-view/watches/view.lua

@@ -57,7 +57,9 @@ local function show_variables(children, reference, line, depth)
 end
 
 M.show = function()
-    -- Since variables aren't ordered, lines may change unexpectedly
+    -- New expressions may prepended
+    -- And lines may be no longer valid if a variable changes (e.g., array's size changes)
+    -- Hence, lines may change unexpectedly
     -- To handle that, always clear the storage table
     for k, _ in pairs(state.expression_views_by_line) do
         state.expression_views_by_line[k] = nil