Method layoutViews

packages/dockview-core/src/splitview/splitview.ts:800–890

* Margin explain: * * For `n` views in a splitview there will be `n-1` margins `m`. * * To fit the margins each view must reduce in size by `(m * (n - 1)) / n`. * * For each view `i` the offet must be adjusted by `m * i/(n - 1)`.

()

     * For each view `i` the offet must be adjusted by `m * i/(n - 1)`.
     */
    private layoutViews(): void {
        this._contentSize = this.viewItems.reduce((r, i) => r + i.size, 0);

        this.updateSashEnablement();

        if (this.viewItems.length === 0) {
            return;
        }

        const visibleViewItems = this.viewItems.filter((i) => i.visible);

        const sashCount = Math.max(0, visibleViewItems.length - 1);
        const marginReducedSize =
            (this.margin * sashCount) / Math.max(1, visibleViewItems.length);

        let totalLeftOffset = 0;
        const viewLeftOffsets: number[] = [];

        const sashWidth = 4; // hardcoded in css

        const runningVisiblePanelCount = this.viewItems.reduce(
            (arr, viewItem, i) => {
                const flag = viewItem.visible ? 1 : 0;
                if (i === 0) {
                    arr.push(flag);
                } else {
                    arr.push(arr[i - 1] + flag);
                }

                return arr;
            },
            [] as number[]
        );

        // calculate both view and cash positions
        this.viewItems.forEach((view, i) => {
            totalLeftOffset += this.viewItems[i].size;
            viewLeftOffsets.push(totalLeftOffset);

            const size = view.visible ? view.size - marginReducedSize : 0;

            const visiblePanelsBeforeThisView = Math.max(
                0,
                runningVisiblePanelCount[i] - 1
            );

            const offset =
                i === 0 || visiblePanelsBeforeThisView === 0
                    ? 0
                    : viewLeftOffsets[i - 1] +
                      (visiblePanelsBeforeThisView / sashCount) *
                          marginReducedSize;

            if (i < this.viewItems.length - 1) {
                // calculate sash position
                const newSize = view.visible
                    ? offset + size - sashWidth / 2 + this.margin / 2
                    : offset;