implement LayoutPart stuffs

src/layouts/layoutpart.ts

@@ -0,0 +1,106 @@
+
+interface ILayoutPart {
+    adjust(area: Rect, tiles: Window[], basis: Window, delta: RectDelta): void;
+    apply(area: Rect, tiles: Window[]): Rect[];
+}
+
+class FillLayoutPart implements ILayoutPart {
+    public adjust(area: Rect, tiles: Window[], basis: Window, delta: RectDelta): void {
+        /* do nothing */
+    }
+
+    public apply(area: Rect, tiles: Window[]): Rect[] {
+        return tiles.map((tile) => {
+            return area;
+        });
+    }
+}
+
+class HalfSplitLayoutPart implements ILayoutPart {
+    public gap: number;
+    public primarySize: number;
+    public ratio: number;
+
+    constructor(
+        public primary: ILayoutPart,
+        public secondary: ILayoutPart,
+    ) {
+        this.gap = 0;
+        this.primarySize = 1;
+        this.ratio = 0.5;
+    }
+
+    public adjust(area: Rect, tiles: Window[], basis: Window, delta: RectDelta): void {
+        const basisIndex = tiles.indexOf(basis);
+        if (basisIndex < 0)
+            return;
+
+        if (tiles.length <= this.primarySize) {
+            /* primary only */
+            this.primary.adjust(area, tiles, basis, delta);
+        } else if (this.primarySize === 0) {
+            /* secondary only */
+            this.secondary.adjust(area, tiles, basis, delta);
+        } else {
+            /* both parts */
+
+            /** which part to adjust. 0 = primary, 1 = secondary */
+            const targetIndex = (basisIndex < this.primarySize) ? 0 : 1;
+
+            this.ratio = LayoutUtils.adjustAreaHalfWeights(
+                area,
+                this.ratio,
+                this.gap,
+                targetIndex,
+                delta,
+                true,
+            );
+
+            ((targetIndex === /* primary */ 0)? this.primary : this.secondary)
+                .adjust(area, tiles, basis, delta);
+        }
+    }
+
+    public apply(area: Rect, tiles: Window[]): Rect[] {
+        if (tiles.length <= this.primarySize) {
+            /* primary only */
+            return this.primary.apply(area, tiles);
+        } else if (this.primarySize === 0) {
+            /* secondary only */
+            return this.secondary.apply(area, tiles);
+        } else {
+            /* both parts */
+            const [primaryArea, secondaryArea] = LayoutUtils.splitAreaHalfWeighted(area, this.ratio, this.gap, true);
+            const primaryResult = this.primary.apply(primaryArea, tiles.slice(0, this.primarySize));
+            const secondaryResult = this.secondary.apply(secondaryArea, tiles.slice(this.primarySize));
+            return primaryResult.concat(secondaryResult);
+        }
+    }
+}
+
+class StackLayoutPart implements ILayoutPart {
+    public gap: number;
+
+    constructor() {
+        this.gap = 0;
+    }
+
+    public adjust(area: Rect, tiles: Window[], basis: Window, delta: RectDelta): void {
+        const weights = LayoutUtils.adjustAreaWeights(
+            area,
+            tiles.map((tile) => tile.weight),
+            CONFIG.tileLayoutGap,
+            tiles.indexOf(basis),
+            delta
+        );
+
+        weights.forEach((weight, i) => {
+            tiles[i].weight = weight * tiles.length;
+        });
+    }
+ 
+    public apply(area: Rect, tiles: Window[]): Rect[] {
+        const weights = tiles.map((tile) => tile.weight);
+        return LayoutUtils.splitAreaWeighted(area, weights, this.gap);
+    }
+}