Make emacs much more usable as an IDE

Fix C-u in evil
Fix 'region theme
Add editorconfig, flycheck, company, and lsp-mode

init.el

@@ -34,7 +34,7 @@
       mouse-wheel-follow-mouse +1
       scroll-step 1) ;; C-n C-p scroll step
 
-;;;; Tabs
+;; Tabs
 (setq custom-tab-width 2)
 
 (defun disable-tabs ()
@@ -79,6 +79,11 @@
 ;; Rainbow-Mode (show hex strings in color)
 (use-package rainbow-mode)
 
+;; Editorconfig support
+(use-package editorconfig
+  :config
+  (editorconfig-mode 1))
+
 ;; Treesitter
 (use-package tree-sitter
   :config
@@ -94,6 +99,7 @@
 ;; Evil (Vim Emulation)
 (use-package evil
   :init
+  (setq evil-want-C-u-scroll t)
   (setq evil-mode-beyond-eol t)
   (setq evil-mode-fine-undo t)
   (setq evil-default-state 'emacs)
@@ -133,3 +139,51 @@
     ;; Define jumps with ] and [
     (funcall define-jumps "c" "class")
     (funcall define-jumps "f" "function")))
+
+;; Explanations for keybindings
+(use-package which-key
+  :config
+  (which-key-mode +1))
+
+;; On the fly syntax checking
+(use-package flycheck)
+
+;; Completions
+(use-package company
+  :init
+  (setq company-minimum-prefix-length 1)
+  (setq company-idle-delay 0)
+  (setq company-selection-wrap-around t)
+  (setq company-tooltip-align-annotations t)
+  (setq company-tooltip-flip-when-above t)
+  (setq company-tooltip-margin 0)
+  (setq company-show-quick-access 'right)
+  :config
+  (setq company-transformers '(delete-consecutive-dups
+                               company-sort-prefer-same-case-prefix
+                               company-sort-by-backend-importance
+                               company-sort-by-occurrence))
+  (define-key company-active-map (kbd "M-`") #'company-complete-selection)
+  (define-key company-active-map (kbd "M-n") #'company-select-next)
+  (define-key company-active-map (kbd "M-p") #'company-select-previous)
+  (define-key company-active-map (kbd "M-j") #'company-select-next)
+  (define-key company-active-map (kbd "M-k") #'company-select-previous)
+  (global-company-mode +1))
+
+;; Lsp
+(use-package lsp-mode
+  :init
+  (setq lsp-headerline-breadcrumb-enable nil)
+  (setq lsp-signature-auto-activate nil)
+  (setq lsp-signature-doc-lines 0)
+  (setq lsp-ui-doc-show-with-cursor t)
+  (setq lsp-ui-doc-position 'top)
+  (setq lsp-ui-doc-delay 0.5)
+  :config
+  (evil-define-key 'normal lsp-mode-map (kbd "SPC l") lsp-command-map)
+  (add-hook 'lsp-mode-hook #'lsp-enable-which-key-integration)
+  (add-hook 'evil-insert-state-entry-hook #'lsp-signature-activate)
+  (add-hook 'evil-insert-state-exit-hook #'lsp-signature-stop))
+(use-package lsp-ui)
+(setq gc-cons-threshold (* 1024 1024 100))
+(setq read-process-output-max (* 1024 1024))

my-theme-theme.el

@@ -61,6 +61,9 @@
        (variable '("#6ec5b1" nil nil))
        (string '("#15e04a" nil nil))
        (type '("#17b343" nil nil))
+
+       (lsp-hover-highlight (funcall brighten-first common-bg 0.05))
+       (company-bg (funcall brighten-first common-bg 0.1))
        ;; Extra colors #1fa345
        ) 
   (custom-theme-set-faces
@@ -72,6 +75,7 @@
    (funcall face 'mode-line-inactive :bg (funcall darken-first common-bg 0.35) :fg common-fg)
    (funcall face 'mode-line :bg modeline :fg common-fg)
    (funcall face 'hl-line :bg (funcall darken-first common-bg 0.15))
+   (funcall face 'region :bg (funcall brighten-first common-bg 0.15))
    (funcall face 'font-lock-comment-face :fg comment)
    (funcall face 'font-lock-doc-face :fg doc)
    (funcall face 'font-lock-keyword-face :fg keyword)
@@ -80,6 +84,17 @@
    (funcall face 'font-lock-variable-name-face :fg variable)
    (funcall face 'font-lock-string-face :fg string)
    (funcall face 'font-lock-type-face :fg type)
+
+   ;; Lsp
+   (funcall face 'lsp-face-highlight-textual :bg lsp-hover-highlight)
+   (funcall face 'lsp-face-highlight-read :bg lsp-hover-highlight)
+   (funcall face 'lsp-face-highlight-write :bg lsp-hover-highlight)
+
+   ;; company
+   (funcall face 'company-tooltip :bg company-bg)
+   (funcall face 'company-tooltip-selection :bg (funcall brighten-first company-bg 0.15))
+   (funcall face 'company-scrollbar-fg :bg (funcall brighten-first company-bg 0.3))
+   (funcall face 'company-scrollbar-bg :bg (funcall brighten-first company-bg 0.15))
    ))
 
 (provide-theme 'my-theme)