hl

This project is WIP and used for exploration

Text displaying tool (to enhance acme workflow) - might become something else in the future.

Why

• Enable some highlighting in my acme workflow, when I need it (screensharing, visual parsing, etc).
• Seemed like an interesting project for me to expand my knowledge and skills.

Dependencies:

• libsdl2-ttf-dev
• libsdl2-dev

TODO:

• tokenizing file
  • based on extension
    • able to override the style
  • words/strings/numbers/tabs/spaces/newlines
  • comments
  • comment keywords
  • code keywords
    • c/cpp/h
    • golang
    • python
    • markdown
    • others when needed
  • golden file testing
  • MAYBE: scoping tokens. i.e. currently stuff in backticks are not easily highlightable via double click
• TUI - print text to terminal
  • intermediate step, serves as backup to GUI
  • auto-update code when it's modified
• GUI with SDL2
  • non-colored text
  • auto-update code when it's modified
  • horizontal/vertical scrolling (unbounded)
  • font increase/decrease
    • ctrl+plus(or ctrl+equal for convenience)/ctrl+minus
    • ctrl+mouse-wheel
    • reset to default
  • keyword based highlighting in GUI
    • multi-line strings are not properly handling newline chars
  • bounded horizontal/vertical scrolling
    • extension: horizontal scrolling only when text doesn't fit the screen
    • extension: able to specify scrolling factor
    • extension: snap back if text fits on screen, but horizontal scroll is non-zero
  • scrollbar (horizontal/vertical)
    • acme inspired movements on scrollbar
  • when font is resized, keep same place in view
    • smaller font increment instead
  • highlighting text with mouse
    • token based highlighting
    • keep highlighting after letting go, stop highlighting after click
    • char based highlighting
    • better accuracy on highlighting
    • mouse scrolling highlight previously highlighted area, instead of moving along
      • store beginning token instead of beginning mouse pos
    • acme-inspired highlighting (inside quotes, parenthesis, brackets etc)
    • double-click to highlight a word
    • triple-click or double click beginning/end of line to highlight a line
  • copy-paste highlighted text
  • colorschemes; currently:
    • light (default)
    • dark
    • gruvbox-light
    • gruvbox-dark
    • solarized-light
    • solarized-dark
  • soft-wrap text
  • row and col numbers
    • goto line nr
    • MAYBE: jump to <path>:<line>:<col> support
  • text search
  • display cursor
  • vendor SDL2 how to vendor:
    • installed libtool-bin and some lib.*-dev packages
    • steps to build SDL2 and SDL2_ttf for vendoring:

     git clone -b SDL2 https://github.com/libsdl-org/SDL.git
     git clone -b SDL2 https://github.com/libsdl-org/SDL_ttf.git
     mkdir vendor
     cd vendor
     mkdir SDL2
     cd SDL; ./configure --prefix=$(pwd)/../SDL2; make -j4; make -j4 install; cd ..
     cd SDL_ttf; ./configure --prefix=$(pwd)/../SDL2 --disable-freetype-builtin --disable-harfbuzz-builtin; make -j4; make -j4 install; cd ..
     PKG_CONFIG_PATH=./SDL2/lib/pkgconfig pkg-config --cflags --libs sdl2 SDL2_ttf # prints include and lib paths, but this has been added to Makefile as well
    
     # compile cmd
     clang -Wall -o ./bin/hl ./main.c -lm `PKG_CONFIG_PATH="./vendor/SDL2/lib/pkgconfig" pkg-config --cflags --libs sdl2 SDL2_ttf`

  • move tokens and textures to state
  • use linked lists for holding tokens/textures instead of array
    • rationale: my hope is that this would enable reasonable enough text editing for this project
  • UTF handling
  • able to specify font
    • cmd args
    • on the fly
  • specify color schemes
    • cmd args
    • on the fly
  • some acme-inspired mouse actions
    • TBD
  • some keyboard shortcuts for navigation
    • ctrl+d/ctrl+u = jump half a page down/up (vim inspired)
    • ctrl+a/ctrl+e = jump to beginning/end of file
    • TBD
  • MAYBE: MAYBE: lsp integration
  • MAYBE: possible performance optimization
    • when font changes scale by factor first, and when the font persists for some time, calculate the textures again.
    • MAYBE: instead of list (of textures/tokens):
      • linked list
      • map
    • MAYBE: compute values/obj only once, that don't need to be recomputed
    • render only rows fitting on window
    • render only columns fitting on window
• fix mem-leaks
• building
  • `make
  • something inspired by nobuild instead of make
• merge tokenize_test into the main file
• commandline arguments to toggle different functionality; eg tui vs gui mode, overriding comment/code style, etc
  • override what to color/what not to color
• resolve TODOs and others
• placeholder
• proper readme
• make it work on other platforms than linux (grep ifdef OSX)

Some Resources

• http://thenumb.at/cpp-course/sdl2/07/07.html
• http://thenumb.at/cpp-course/sdl2/08/08.html
• https://dev.to/deusinmachina/sdl-tutorial-in-c-part-2-displaying-text-o55
• https://dev.to/noah11012/using-sdl2-opening-a-window-79c

Author

Meelis Utt