Add patch/diff file highlighting

Added patch/diff file highlighting for easy at a glance viewing.

Does not try to highlight based on language, just a simple green for additions
and red for deletions, plus some extra colours for metadata.

(This could be changed in the future if we did want to highlight per language
since the regions I added could stay the same and just change the token
colours... That would involve needing to detect language based on the file
extensions of the diff'd files though which might be kind of slow, especially
for large patches that involve many files.)

src/buffer.jai

@@ -1598,6 +1598,7 @@ get_tokenize_function :: (lang: Buffer.Lang) -> Tokenize_Function {
         case .Css;                  return tokenize_css;
         case .CSharp;               return tokenize_csharp;
         case .D;                    return tokenize_d;
+        case .Diff;                 return tokenize_diff;
         case .Glsl;                 return tokenize_glsl;
         case .Hlsl;                 return tokenize_hlsl;
         case .Golang;               return tokenize_golang;
@@ -1839,6 +1840,7 @@ Buffer :: struct {
         Css;
         CSharp;
         D;
+        Diff;
         Glsl;
         Hlsl;
         Golang;
@@ -1914,6 +1916,9 @@ Buffer_Region :: struct {
         scope_module;
 
         heredoc;
+
+        addition;
+        deletion;
     }
 }
 

src/colors.jai

@@ -52,6 +52,8 @@ Color :: enum u8 {
     REGION_WARNING;
     REGION_ERROR;
     REGION_HEREDOC;
+    REGION_ADDITION;
+    REGION_DELETION;
 
     BUILD_PANEL_BACKGROUND;
     BUILD_PANEL_SCROLLBAR;

src/config.jai

@@ -1,6 +1,6 @@
 // Increment this if your PR adds a setting, color or default keybinding (and amend the relevant array
 // in config_migrator.jai).  You don't need to increase it for each such change; once per PR is fine.
-CURRENT_CONFIG_VERSION :: 16;
+CURRENT_CONFIG_VERSION :: 17;
 
 load_global_config :: (fallback_to_default_on_failure := false, force := false) -> success: bool, changed: bool, there_were_warnings: bool {
     config_path := tprint("%/global.focus-config", config_dir);

src/config_migrator.jai

@@ -581,6 +581,11 @@ ADDED_COLORS :: Added_Color.[
 
     .{ 8, "bracket_highlight",                "selection_highlight",    "E8FCFE30" },
     .{ 8, "indent_guide",                     "selection_highlight",    "FCEDFC26" },
+
+    .{ 17, "code_addition",                   "",                       "33B333FF" },
+    .{ 17, "region_addition",                 "",                       "2260224C" },
+    .{ 17, "code_deletion"  ,                 "",                       "E64D4DFF" },
+    .{ 17, "region_deletion",                 "",                       "7722224C" },
 ];
 
 

src/config_parser.jai

@@ -235,6 +235,8 @@ map_name_to_color :: (name: string) -> Color {
         case "region_warning";                          return .REGION_WARNING;
         case "region_error";                            return .REGION_ERROR;
         case "region_heredoc";                          return .REGION_HEREDOC;
+        case "region_addition";                         return .REGION_ADDITION;
+        case "region_deletion";                         return .REGION_DELETION;
 
         case "build_panel_background";                  return .BUILD_PANEL_BACKGROUND;
         case "build_panel_scrollbar";                   return .BUILD_PANEL_SCROLLBAR;

src/draw.jai

@@ -3889,6 +3889,8 @@ get_region_color :: (kind: Buffer_Region.Kind) -> Color {
         case .success;          color = Color.REGION_SUCCESS;
         case .warning;          color = Color.REGION_WARNING;
         case .error;            color = Color.REGION_ERROR;
+        case .addition;         color = Color.REGION_ADDITION;
+        case .deletion;         color = Color.REGION_DELETION;
     }
     return color;
 }

src/editors.jai

@@ -1347,6 +1347,9 @@ get_lang_from_path :: (full_path: string) -> Buffer.Lang {
 
         case "ini";             lang = .Ini;
 
+        case "diff";            lang = .Diff;
+        case "patch";           lang = .Diff;
+
         case;
             // Files named `.focus_config` are assumed to have no extension
             if equal_nocase(basename_with_extension, ".focus-config") then lang = .Focus_Config;
@@ -3483,6 +3486,7 @@ toggle_comment :: (editor: *Editor, buffer: *Buffer, is_fallback := false) {
         // No support for comments at all
         case .Plain_Text;        #through;
         case .Todo;              #through;
+        case .Diff;              #through;
         case .Focus_Build_Panel;
             return;
     }
@@ -3712,6 +3716,7 @@ toggle_block_comment :: (editor: *Editor, buffer: *Buffer, is_fallback := false)
         // No support for comments at all
         case .Plain_Text;        #through;
         case .Todo;              #through;
+        case .Diff;              #through;
         case .Focus_Build_Panel;
             return;
     }

src/langs/common.jai

@@ -357,4 +357,7 @@ Token_Type :: enum u8 {
     header4;
     header5;
     header6;
+
+    addition;
+    deletion;
 }

src/langs/diff.jai

@@ -0,0 +1,145 @@
+tokenize_diff :: (using buffer: *Buffer, start_offset := -1, count := -1) -> [] Buffer_Region {
+    tokenizer: Diff_Tokenizer;
+    tokenizer.base = get_tokenizer(buffer, start_offset, count);
+
+    while true {
+        token := get_next_token(*tokenizer);
+        if token.type == .eof break;
+
+        memset(tokens.data + token.start, xx token.type, token.len);
+    }
+
+    if tokenizer.current_region_id >= 0 then end_region(*tokenizer, tokenizer.t - tokenizer.buf.data);
+    quick_sort(tokenizer.regions, (a, b) => (a.start - b.start));
+    return tokenizer.regions;
+}
+
+#scope_file
+
+get_next_token :: (using tokenizer: *Diff_Tokenizer) -> Token {
+    token := Token.{
+        start = cast(s32) (t - buf.data),
+        type  = .eof,
+    };
+
+    if t >= max_t return token;
+
+    start_t = t;
+    char := t.*;
+
+    if char == {
+        case #char "+"; parse_plus     (tokenizer, *token);
+        case #char "-"; parse_minus    (tokenizer, *token);
+        case #char "@"; parse_range    (tokenizer, *token);
+        case #char " "; parse_unchanged(tokenizer, *token);
+        case;           parse_metadata (tokenizer, *token);
+    }
+
+    if t >= max_t then t = max_t;
+    token.len = cast(s32) (t - start_t);
+    return token;
+}
+
+parse_plus :: (using tokenizer: *Diff_Tokenizer, token: *Token) {
+    token.type = .addition;
+
+    t += 1;
+    if t >= max_t then return;
+
+    current := t.*;
+    next    := (t + 1).*;
+    if current == #char "+" && next == #char "+" {
+        eat_until_newline(tokenizer);
+        t += 1;
+    }
+    else {
+        if current_region_id == -1 || regions[current_region_id].kind != .addition {
+            start_region(tokenizer, token.start, .addition);
+        }
+        eat_until_newline(tokenizer);
+        t += 1;
+    }
+
+    if t > max_t then t = max_t;
+}
+
+parse_minus :: (using tokenizer: *Diff_Tokenizer, token: *Token) {
+    token.type = .deletion;
+
+    t += 1;
+    if t >= max_t then return;
+
+    current := t.*;
+    next    := (t + 1).*;
+    if current == #char "-" && next == #char "-" {
+        eat_until_newline(tokenizer);
+        t += 1;
+    }
+    else {
+        if current_region_id == -1 || regions[current_region_id].kind != .deletion {
+            start_region(tokenizer, token.start, .deletion);
+        }
+        eat_until_newline(tokenizer);
+        t += 1;
+    }
+
+    if t > max_t then t = max_t;
+}
+
+parse_range :: (using tokenizer: *Diff_Tokenizer, token: *Token) {
+    t += 1;
+    if t >= max_t || t.* != #char "@" {
+        parse_metadata(tokenizer, token);
+        return;
+    }
+
+    token.type = .number;
+    if current_region_id != -1 then end_region(tokenizer, token.start);
+    eat_until_newline(tokenizer);
+    t += 1;
+}
+
+parse_unchanged :: (using tokenizer: *Diff_Tokenizer, token: *Token) {
+    token.type = .identifier;
+    if current_region_id != -1 then end_region(tokenizer, token.start);
+    eat_until_newline(tokenizer);
+    t += 1;
+}
+
+parse_metadata :: (using tokenizer: *Diff_Tokenizer, token: *Token) {
+    token.type = .string_literal;
+    if current_region_id != -1 then end_region(tokenizer, token.start);
+    eat_until_newline(tokenizer);
+    t += 1;
+}
+
+start_region :: (using tokenizer: *Diff_Tokenizer, offset: s64, kind: Buffer_Region.Kind) {
+    if current_region_id >= 0 then end_region(tokenizer, offset);
+    current_region_id = regions.count;
+
+    region := Buffer_Region.{
+        start = xx offset,
+        end   = -1,
+        kind  = kind,
+    };
+    array_add(*regions, region);
+}
+
+end_region :: inline (using tokenizer: *Diff_Tokenizer, offset: s64) {
+    regions[current_region_id].end = xx offset;
+    current_region_id = -1;
+}
+
+Diff_Tokenizer :: struct {
+    using #as base: Tokenizer;
+
+    regions: [..] Buffer_Region;
+    regions.allocator = temp;
+    current_region_id := -1;
+}
+
+Token :: struct {
+    start, len: s32;
+    type: Token_Type;
+}
+

src/main.jai

@@ -1010,6 +1010,7 @@ focus_allocator: Allocator;
 #load "langs/batch.jai";
 #load "langs/swift.jai";
 #load "langs/ini.jai";
+#load "langs/diff.jai";
 
 #if OS == .WINDOWS {
     #load "platform/windows.jai";

src/widgets/color_preview.jai

@@ -302,6 +302,7 @@ get_language_sample_text :: (lang: Buffer.Lang) -> string {
         case .Css;               return SAMPLE_Css;
         case .CSharp;            return SAMPLE_CSharp;
         case .D;                 return SAMPLE_D;
+        case .Diff;              return SAMPLE_Diff;
         case .Glsl;              return SAMPLE_Glsl;
         case .Hlsl;              return SAMPLE_Hlsl;
         case .Golang;            return SAMPLE_Golang;

src/widgets/color_preview_samples.jai

@@ -291,8 +291,8 @@ main :: proc() {
 }
 
 Structure :: struct {
-    is_true:    bool,
-    text:        string,
+    is_true: bool,
+    text:    string,
 }
 
 ODIN
@@ -1251,3 +1251,62 @@ lines"
 StillOk = true
 
 LANG_INI
+
+SAMPLE_Diff :: #string LANG_Diff
+diff --git a/src/draw.jai b/src/draw.jai
+index 6711110..e7b4234 100644
+--- a/src/draw.jai
++++ b/src/draw.jai
+@@ -3761,7 +3761,7 @@ get_new_scroll_target_from_scrollbar :: (main_rect: Rect, content_height: float,
+ draw_scrollbar :: (main_rect: Rect, content_height: float, scroll: s32, scroll_target: s32, max_scroll: s32, ui_id: Ui_Id, for_build_panel := false, $draw := true) -> new_scroll_target: s32 {
+     scroll_target = clamp(scroll_target, 0, max_scroll);
+
+-    if scroll != scroll_target then start_scrollbar_fade_out_animation(ui_id, initial_value = config.settings.scrollbar_max_opacity);
++    if scroll != scroll_target then start_scrollbar_fade_out_animation(ui_id);
+
+     if max_scroll <= 0 return scroll_target;
+
+@@ -3955,7 +3955,9 @@ is_hovering_over :: (ui_id: Ui_Id) -> bool {
+     return (ui.hot_last_frame == ui_id && ui.active == .none) || ui.active == ui_id;
+ }
+
+-start_scrollbar_fade_out_animation :: (ui_id: Ui_Id, initial_value := 1.0) {
++start_scrollbar_fade_out_animation :: (ui_id: Ui_Id, initial_value := -1.0) {
++    if initial_value < 0 then initial_value = config.settings.scrollbar_max_opacity;
++
+     animation: *Scrollbar_Fade_Out_Animation;
+     for * scrollbar_fade_out_animations {
+         if it.ui_id == ui_id { animation = it; break; }
+@@ -3967,6 +3969,7 @@ start_scrollbar_fade_out_animation :: (ui_id: Ui_Id, initial_value := 1.0) {
+     start_animation(*animation.anim, initial_value, 0.0, delay = config.settings.scrollbar_fade_out_delay_seconds);
+ }
+
++
+ #scope_export
+
+ Icon :: enum u16 {
+diff --git a/src/editors.jai b/src/editors.jai
+index fa5ae21..3bc8ebf 100644
+--- a/src/editors.jai
++++ b/src/editors.jai
+@@ -2320,13 +2320,15 @@ move_cursors_by_page :: (editor: *Editor, buffer: Buffer, dir: enum { up; down;
+     page_size := cast(s32) (window_height / line_height);
+
+     for * cursor : editor.cursors {
+-        line := offset_to_line(editor, buffer, cursor.pos);
++        coords := offset_to_coords(editor, buffer, cursor.pos);
+         if dir == .up {
+-            line -= page_size;
++            coords.line -= page_size;
+         } else {
+-            line += page_size;
++            coords.line += page_size;
+         }
+-        cursor.pos = coords_to_offset(editor, buffer, Coords.{ line = line, col = cursor.col_wanted });
++        if cursor.col_wanted < 0 then cursor.col_wanted = coords.col;
++        coords.col = cursor.col_wanted;
++        cursor.pos = coords_to_offset(editor, buffer, coords);
+     }
+
+     if dir == .up  editor.cursor_moved = .moved_up;
+LANG_Diff