overleaf/services/web/frontend/js/ide/directives/verticalResizablePanes.js

import App from '../../base'

export default App.directive('verticalResizablePanes', [
  'localStorage',
  'ide',
  function (localStorage, ide) {
    return {
      restrict: 'A',
      link(scope, element, attrs) {
        const name = attrs.verticalResizablePanes
        const minSize = scope.$eval(attrs.verticalResizablePanesMinSize)
        const maxSize = scope.$eval(attrs.verticalResizablePanesMaxSize)
        const defaultSize = scope.$eval(attrs.verticalResizablePanesDefaultSize)
        let storedSize = null
        let manualResizeIncoming = false

        if (name) {
          const storageKey = `vertical-resizable:${name}:south-size`
          storedSize = localStorage(storageKey)
          $(window).unload(() => {
            if (storedSize) {
              localStorage(storageKey, storedSize)
            }
          })
        }

        const layoutOptions = {
          center: {
            paneSelector: '[vertical-resizable-top]',
            paneClass: 'vertical-resizable-top',
            size: 'auto',
          },
          south: {
            paneSelector: '[vertical-resizable-bottom]',
            paneClass: 'vertical-resizable-bottom',
            resizerClass: 'vertical-resizable-resizer',
            resizerCursor: 'ns-resize',
            size: 'auto',
            resizable: true,
            closable: false,
            slidable: false,
            spacing_open: 6,
            spacing_closed: 6,
            maxSize: '75%',
          },
        }

        const toggledExternally =
          attrs.verticalResizablePanesToggledExternallyOn
        const hiddenExternally = attrs.verticalResizablePanesHiddenExternallyOn
        const hiddenInitially = attrs.verticalResizablePanesHiddenInitially
        const resizeOn = attrs.verticalResizablePanesResizeOn
        const resizerDisabledClass = `${layoutOptions.south.resizerClass}-disabled`

        function enableResizer() {
          if (layoutHandle.resizers && layoutHandle.resizers.south) {
            layoutHandle.resizers.south.removeClass(resizerDisabledClass)
          }
        }

        function disableResizer() {
          if (layoutHandle.resizers && layoutHandle.resizers.south) {
            layoutHandle.resizers.south.addClass(resizerDisabledClass)
          }
        }

        function handleDragEnd() {
          manualResizeIncoming = true
        }

        function handleResize(paneName, paneEl, paneState) {
          if (manualResizeIncoming) {
            storedSize = paneState.size
          }
          manualResizeIncoming = false
        }

        if (toggledExternally) {
          scope.$on(toggledExternally, (e, open) => {
            if (open) {
              enableResizer()
              layoutHandle.sizePane(
                'south',
                storedSize ?? defaultSize ?? 'auto'
              )
            } else {
              disableResizer()
              layoutHandle.sizePane('south', 'auto')
            }
          })
        }

        if (hiddenExternally) {
          ide.$scope.$on(hiddenExternally, (e, open) => {
            if (open) {
              layoutHandle.show('south')
            } else {
              layoutHandle.hide('south')
            }
          })
        }

        if (resizeOn) {
          ide.$scope.$on(resizeOn, () => {
            ide.$timeout(() => {
              layoutHandle.resizeAll()
            })
          })
        }

        if (maxSize) {
          layoutOptions.south.maxSize = maxSize
        }

        if (minSize) {
          layoutOptions.south.minSize = minSize
        }

        if (defaultSize) {
          layoutOptions.south.size = defaultSize
        }

        // The `drag` event fires only when the user manually resizes the panes; the `resize` event fires even when
        // the layout library internally resizes itself. In order to get explicit user-initiated resizes, we need to
        // listen to `drag` events. However, when the `drag` event fires, the panes aren't yet finished sizing so we
        // get the pane size *before* the resize happens. We do get the correct size in the next `resize` event.
        // The solution to work around this is to set up a flag in `drag` events which tells the next `resize` event
        // that it was user-initiated (therefore, storing the value).
        layoutOptions.south.ondrag_end = handleDragEnd
        layoutOptions.south.onresize = handleResize

        const layoutHandle = element.layout(layoutOptions)
        if (hiddenInitially === 'true') {
          layoutHandle.hide('south')
        }
      },
    }
  },
])