Method onPointerStart

packages/dockview-core/src/splitview/splitview.ts:437–567

(event: PointerEvent)

            sash.className = 'dv-sash';

            const onPointerStart = (event: PointerEvent) => {
                for (const item of this.viewItems) {
                    item.enabled = false;
                }

                const iframes = disableIframePointEvents();

                const start =
                    this._orientation === Orientation.HORIZONTAL
                        ? event.clientX
                        : event.clientY;

                const sashIndex = firstIndex(
                    this.sashes,
                    (s) => s.container === sash
                );

                //
                const sizes = this.viewItems.map((x) => x.size);

                //
                let snapBefore: ISashDragSnapState | undefined;
                let snapAfter: ISashDragSnapState | undefined;
                const upIndexes = range(sashIndex, -1);
                const downIndexes = range(sashIndex + 1, this.viewItems.length);
                const minDeltaUp = upIndexes.reduce(
                    (r, i) => r + (this.viewItems[i].minimumSize - sizes[i]),
                    0
                );
                const maxDeltaUp = upIndexes.reduce(
                    (r, i) =>
                        r + (this.viewItems[i].viewMaximumSize - sizes[i]),
                    0
                );
                const maxDeltaDown =
                    downIndexes.length === 0
                        ? Number.POSITIVE_INFINITY
                        : downIndexes.reduce(
                              (r, i) =>
                                  r +
                                  (sizes[i] - this.viewItems[i].minimumSize),
                              0
                          );
                const minDeltaDown =
                    downIndexes.length === 0
                        ? Number.NEGATIVE_INFINITY
                        : downIndexes.reduce(
                              (r, i) =>
                                  r +
                                  (sizes[i] -
                                      this.viewItems[i].viewMaximumSize),
                              0
                          );
                const minDelta = Math.max(minDeltaUp, minDeltaDown);
                const maxDelta = Math.min(maxDeltaDown, maxDeltaUp);
                const snapBeforeIndex = this.findFirstSnapIndex(upIndexes);
                const snapAfterIndex = this.findFirstSnapIndex(downIndexes);
                if (typeof snapBeforeIndex === 'number') {