gristlabs_grist-core/app/client/components/LayoutEditor.ts

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/**
* The LayoutEditor can be attached to a Layout object to allow changing it.
*
* Issues:
* TODO: Hitting ESC while dragging should revert smoothly. We can collapse the original leaf, but
* not remove it. On Cancel, we would uncollapse it, and remove the newly-inserted targetBox.
* TODO: UNDO should work. It's OK to just rebuild the old layout without any transition. In other
* words, this may be fine to do fully outside of LayoutEditor.
* TODO: if mouseup over an active hint of the DropTargeter, it might be a better experience to
* reposition to that spot.
*
* TEST CASES THAT SHOULD BE VERIFIED AFTER ANY CHANGE.
* These refer to test/client/components/sampleLayout.js, testable at
* http://localhost:8080/testKoForm.html#topTab=4.
* 1. Drag #1 down and up its container element, pausing at borders. Elements around that border
* should smoothly float to open space for it. Dropping it should cause no jumps.
* 2. Drag #1 down to top of #6. A grey "drop target" rectangle should appear. Hovering over it
* should open space over #6. After that, dragging to bottom of #6 and back to top of #6 should
* open the space automatically without the "drop target".
* 3. Drag #3 right and left in its container, pausing at borders. Elements should again smoothly
* float to open space for it. Dropping it should cause no jumps.
* 4. Drag #4 down into #5, positioning above #5, below, to the left (splitting #5 horizontally)
* or to the right.
* 5. Drop #4 onto the leftmost "drop target" on the left side of #5. It should end up as 1/3 of
* the width of the entire layout, spanning the full height above #6. Drop it back to its place
* between #3 and #9.
* 6. Resizing: every vertical line should allow dragging it left or right to resize. The "resize"
* mouse pointer should appear over a few pixels to the left and right of the border, it should
* not be a difficult area to target. (This gets messed up if overflow:hidden is set on the box
* elements.)
* 7. Drag box 3 to trash; hovering should make it disappear from Layout, mousing back should
* bring it back. Mouse-up over the trash icon should leave it out of the layout.
* 8. Drag boxes 3, 9, 10, 2, 7, 1 (8 should stretch vertically), 5 to trash. They should
* disappear with other elements shrinking or expanding to close the gap.
* 9. Adding a new element: Drag "+ Add New" box to between 1 and 2. A "drop target" should
* appear, allowing you to insert it. Same for adding between 3 and 4. Should be no jumps.
* 10. Drag new element to above #3: three possible drop targets should appear. Hover over each in
* turn, starting from the bottommost part, and make sure it gets inserted in the right level.
*/
import {extend, noop, pick} from 'underscore';
import {observable, removeNode, utils} from 'knockout';
import assert from 'assert';
import Promise from 'bluebird';
import {Events as BackboneEvents} from 'backbone';
import {Disposable, emptyNode} from 'app/client/lib/dispose';
import {Delay} from 'app/client/lib/Delay';
import dom from 'app/client/lib/dom';
import koDom from 'app/client/lib/koDom';
import {ContentBox, Layout, LayoutBox} from './Layout';
import * as ko from 'knockout';
import {get as getBrowserGlobals} from 'app/client/lib/browserGlobals';
/**
* Use the browser globals in a way that allows replacing them with mocks in tests.
*/
const G = getBrowserGlobals('document', 'window', '$');
//----------------------------------------------------------------------
class HelperBox {
public box!: LayoutBox;
public scalePerFlexUnit: number = 0;
public nextSiblings: LayoutBox[] = [];
public origNextSizes: number[] = [];
public origSize: number = 0;
public sumAll: number = 0;
public sumPrev: number = 0;
public sumNext: number = 0;
constructor(data?: Partial<HelperBox>) {
if (data) {
extend(this, data);
}
}
}
interface TargetPart {
box: LayoutBox;
isChild: boolean;
isAfter: boolean;
}
interface JqueryUI {
size: { width: number, height: number };
position: { left: number, top: number };
originalPosition: { left: number, top: number };
originalSize: { width: number, height: number };
}
/**
* The Floater class represents a floating version of the element being dragged around. Its size
* corresponds to the box being dragged. It lets the user see what's being repositioned.
*/
class Floater extends Disposable implements ContentBox {
public leafId: ko.Observable<string | null>;
public leafContent: ko.Observable<Element | null>;
public fillWindow: boolean;
public floaterElem: HTMLElement;
public mouseOffsetX: number;
public mouseOffsetY: number;
public lastMouseEvent: MouseEvent | null;
public create(fillWindow?: boolean) {
this.leafId = observable<string|null>(null);
this.leafContent = observable<Element | null>(null);
this.fillWindow = fillWindow || false;
this.floaterElem = this.autoDispose(dom('div.layout_editor_floater',
koDom.show(this.leafContent),
koDom.scope(this.leafContent, (leafContent: Element) => {
return leafContent;
})
));
G.document.body.appendChild(this.floaterElem);
this.mouseOffsetX = 0;
this.mouseOffsetY = 0;
this.lastMouseEvent = null;
}
public onInitialMouseMove(mouseEvent: MouseEvent, sourceBox: LayoutBox) {
const rect = sourceBox.dom!.getBoundingClientRect();
this.floaterElem.style.width = rect.width + 'px';
this.floaterElem.style.height = rect.height + 'px';
this.mouseOffsetX = 0.2 * rect.width;
this.mouseOffsetY = 0.1 * rect.height;
this.onMouseMove(mouseEvent);
this.leafId(sourceBox.leafId());
this.leafContent(sourceBox.leafContent());
// We use a dummy non-null leafId here, to ensure that sourceBox remains considered a leaf.
sourceBox.leafId('empty');
sourceBox.leafContent(dom('div.layout_editor_empty_space',
koDom.style('margin', (rect.height * 0.02) + 'px'),
koDom.style('min-height', (rect.height * 0.96) + 'px')
));
}
public onMouseUp() {
this.lastMouseEvent = null;
}
public onMouseMove(mouseEvent: MouseEvent) {
this.lastMouseEvent = mouseEvent;
this.floaterElem.style.left = (mouseEvent.clientX - this.mouseOffsetX) + 'px';
this.floaterElem.style.top = (mouseEvent.clientY - this.mouseOffsetY) + 'px';
}
}
//----------------------------------------------------------------------
/**
* DropOverlay is a rectangular indicator that's displayed over a leaf box under the mouse
* pointer, and shows regions of affinity towards one of the borders. It also computes which
* region the user is targeting, and returns an affinity value.
*/
class DropOverlay extends Disposable {
public overlayElem: HTMLElement;
public overlayRect: DOMRect|null;
public hBorder: number | null;
public vBorder: number | null;
public create() {
this.overlayElem = this.autoDispose(dom('div.layout_editor_drop_overlay'));
this.overlayRect = null;
this.hBorder = null;
this.vBorder = null;
}
/**
* Hides the overlay box by detaching it from the current element, if any.
*/
public detach() {
if (this.overlayElem.parentNode) {
this.overlayElem.parentNode.removeChild(this.overlayElem);
}
}
/**
* Shows the overlay box over the given element.
*/
public attach(targetElem: HTMLElement) {
const rect = this.overlayRect = targetElem.getBoundingClientRect();
/*
// If uncommented, this will show areas of affinity when hovering over a box. This is helpful in
// debugging, and may be helpful to users too, but makes the interface feel more cluttered.
if (this.overlayElem.parentNode !== targetElem) {
// This also automatically removes it from the old parent, if any.
targetElem.appendChild(this.overlayElem);
}
*/
// Areas of affinity are essentially fat borders, proportional to width and height. In addition,
// to avoid overly disproportionate regions, we use twice the smaller dimension to limit the
// larger dimension.
this.hBorder = Math.floor(Math.min(rect.height, rect.width * 2) / 3);
this.vBorder = Math.floor(Math.min(rect.width, rect.height * 2) / 3);
const s = this.overlayElem.style;
s.borderTopWidth = s.borderBottomWidth = this.hBorder + 'px';
s.borderLeftWidth = s.borderRightWidth = this.vBorder + 'px';
}
/**
* If the mouse is over a region of affinity, returns the affinity as an 0-3 integer (see
* AFFINITY_NAMES above). Otherwise, returns -1.
*/
public getAffinity(mouseEvent: MouseEvent) {
const rect = this.overlayRect!;
const x = mouseEvent.clientX - rect.left, y = mouseEvent.clientY - rect.top;
const top = getFrac(y, this.hBorder!), down = getFrac(rect.height - y, this.hBorder!);
const left = getFrac(x, this.vBorder!), right = getFrac(rect.width - x, this.vBorder!);
const minValue = Math.min(top, down, left, right);
return (minValue === Infinity ? -1 : [top, down, left, right].indexOf(minValue));
}
}
//----------------------------------------------------------------------
/**
* DropTargeter displays a set of rectangles, each of which represents a particular allowed
* insertion point for the element being dragged. It only shows the insertion points at the edge
* of a particular layoutBox as indicated by DropOverlay.
*/
class DropTargeter extends Disposable {
public listenTo: BackboneEvents["listenTo"];
public trigger: BackboneEvents["trigger"];
public stopListening: BackboneEvents["stopListening"];
public rootElem: HTMLElement;
public targetsDom: HTMLElement|null;
public currentBox: LayoutBox | null;
public currentAffinity: number | null;
public delayedInsertion: Delay;
public activeTarget: TargetPart|null;
public create(rootElem: HTMLElement) {
this.rootElem = rootElem;
this.targetsDom = null;
this.currentBox = null;
this.currentAffinity = null;
this.delayedInsertion = Delay.create();
this.activeTarget = null;
this.autoDisposeCallback(this.removeTargetHints);
}
public removeTargetHints() {
this.activeTarget = null;
this.delayedInsertion.cancel();
if (this.targetsDom) {
removeNode(this.targetsDom);
this.targetsDom = null;
}
this.currentBox = null;
this.currentAffinity = null;
}
public updateTargetHints(
layoutBox: LayoutBox|null,
affinity: number,
overlay: DropOverlay,
prevTargetBox: LayoutBox
) {
// Nothing to update.
if (!layoutBox || (layoutBox === this.currentBox && affinity === this.currentAffinity)) {
return;
}
this.removeTargetHints();
if (affinity === -1) {
return;
}
this.currentBox = layoutBox;
this.currentAffinity = affinity;
const upDown = isAffinityUpDown(affinity);
const isAfter = isAffinityAfter(affinity);
const targetParts: TargetPart[] = [];
// Allow dragging a leaf into another leaf as a child, splitting the latter into two.
// But don't allow dragging a leaf box into itself, that makes no sense.
if (upDown === layoutBox.isVBox() && layoutBox !== prevTargetBox) {
targetParts.push({box: layoutBox, isChild: true, isAfter: isAfter});
}
while (layoutBox) {
if (upDown === layoutBox.isHBox()) {
const children = layoutBox.childBoxes.peek();
// If one of two children is prevTargetBox, replace the last target hint since it
// will be redundant once prevTargetBox is removed.
if (children.length === 2 && prevTargetBox.parentBox() === layoutBox) {
targetParts.splice(targetParts.length - 1, 1,
{box: layoutBox, isChild: false, isAfter: isAfter});
}
// If there is only one child (which may happen for the root box), the target hint
// is redundant.
else if (prevTargetBox !== layoutBox && prevTargetBox !== layoutBox.getSiblingBox(isAfter) &&
children.length !== 1) {
targetParts.push({box: layoutBox, isChild: false, isAfter: isAfter});
}
if (isAfter && !layoutBox.isLastChild()) { break; }
if (!isAfter && !layoutBox.isFirstChild()) { break; }
}
layoutBox = layoutBox.parentBox();
}
if (targetParts.length === 0) {
return;
}
// Render the hint parts.
if (!isAfter) {
targetParts.reverse();
}
// The same code works for both horizontal and vertical situation. For ease of thinking about
// it, we pretend below that we are dealing with an up-down situation (drop hints are horizontal
// wide boxes stacked vertically), and use properties that are named using the up-down
// situation, but whose values might reflect a left-right situation.
const pTop = upDown ? 'top' : 'left', pHeight = upDown ? 'height' : 'width',
pLeft = upDown ? 'left' : 'top', pWidth = upDown ? 'width' : 'height';
let totalHeight = upDown ? overlay.hBorder! : overlay.vBorder!;
const singleHeight = Math.floor(totalHeight / targetParts.length);
// Adjust to account for the rounding-down above.
totalHeight = singleHeight * targetParts.length;
const outerRect = this.rootElem.getBoundingClientRect();
const innerRect = this.currentBox.dom!.getBoundingClientRect();
const self = this;
this.targetsDom = dom('div.layout_editor_drop_targeter',
koDom.style(pTop,
(innerRect[pTop] - outerRect[pTop] +
(isAfter ? innerRect[pHeight] - totalHeight : 0)) + 'px'
),
targetParts.map((part, index) => {
const rect = part.box.dom!.getBoundingClientRect();
return dom('div.layout_editor_drop_target', (elem: HTMLDivElement) => {
elem.style[pHeight] = (singleHeight + 1) + 'px'; // 1px of overlap for better looks
elem.style[pWidth] = rect[pWidth] + 'px';
elem.style[pLeft] = (rect[pLeft] - outerRect[pLeft]) + 'px';
elem.style[pTop] = (singleHeight * index) + 'px';
},
dom.on('mouseenter', function(this: HTMLElement) {
this.classList.add("layout_hover");
self.activeTarget = part;
const padDir = upDown ? (isAfter ? 'Bottom' : 'Top') : (isAfter ? 'Right' : 'Left');
const padding = 'padding' + padDir;
part.box.dom!.style.transition = 'padding .3s';
part.box.dom!.style[padding as any] = '20px';
}),
dom.on('mouseleave', function(this: HTMLElement) {
this.classList.remove("layout_hover");
self.activeTarget = null;
part.box.dom!.style.padding = '0';
}),
dom.on('transitionend', this.triggerInsertion.bind(this, part))
);
})
);
this.rootElem.appendChild(this.targetsDom!);
}
public triggerInsertion(part: TargetPart) {
this.removeTargetHints();
this.trigger('insertBox', (box: LayoutBox) => {
if (part.isChild) {
part.box.addChild(box, part.isAfter);
} else {
part.box.addSibling(box, part.isAfter);
}
});
}
public accelerateInsertion() {
if (this.activeTarget) {
this.activeTarget.box.dom!.style.transition = '';
this.activeTarget.box.dom!.style.padding = '0';
this.triggerInsertion(this.activeTarget);
}
}
}
extend(DropTargeter.prototype, BackboneEvents);
//----------------------------------------------------------------------
/**
* When a LayoutEditor is created for a given Layout object, it makes it possible to drag
* LayoutBoxes to change the layout.
*
* When a user drags a box, its content migrates temporarily to the Floater element, which moves
* with the mouse cursor. As the user drags, the space for the element will open up here or there,
* by adding an appropriate empty targetBox. DropOverlay and DropTargeter together decide the
* insertion point for the drag operations.
*
* NOTES:
* There is some awkwardness in sizing: in a vertically laid out box, the last box takes up all
* available space, so moving it away does not show a transition (the box transitions to empty in
* theory, but it still takes all the same available space).
*/
export class LayoutEditor extends Disposable {
public layout: Layout;
public rootElem: HTMLElement;
public floater: Floater;
public dropOverlay: DropOverlay;
public dropTargeter: DropTargeter;
public measuringBox: HTMLElement;
public listenTo: BackboneEvents["listenTo"];
public trigger: BackboneEvents["trigger"];
public stopListening: BackboneEvents["stopListening"];
public transitionPromise: Promise<void>;
public trashDelay: Delay;
public originalBox: LayoutBox|null;
public targetBox: LayoutBox|null;
public boundMouseDown: (ev: MouseEvent, el: HTMLElement) => void;
public boundMouseMove: (ev: MouseEvent, el: HTMLElement) => void;
public boundMouseUp: (ev: MouseEvent, el: HTMLElement) => void;
public initialMouseDown: boolean;
public lastTriggered: string;
public create(layout: Layout) {
this.layout = layout;
this.rootElem = layout.rootElem;
this.layout.buildLayout(this.layout.getLayoutSpec(), true);
this.floater = this.autoDispose(Floater.create(this.layout.fillWindow));
this.dropOverlay = this.autoDispose(DropOverlay.create());
this.dropTargeter = this.autoDispose(DropTargeter.create(this.rootElem));
this.listenTo(this.dropTargeter, 'insertBox', this.onInsertBox);
// This is a place to put LayoutBoxes that should NOT be shown, but SHOULD be possible to
// measure. It's used when a new box is being moved into the editor.
this.measuringBox = this.autoDispose(dom('div.layout_editor_measuring_box'));
this.rootElem.appendChild(this.measuringBox);
// For better experience, we prevent new repositions while a transition is active, and we
// require some work (leaving and re-entering affinity area) after a previous transition ends.
this.transitionPromise = Promise.resolve();
this.trashDelay = Delay.create();
// TODO: We don't use originalBox at the moment, but may want to, specifically to collapse it
// without removing, and restore if the user hits "Escape".
// This is the box the user clicked, to move its content elsewhere.
this.originalBox = null;
// The new box into which the content is to be inserted. During a move operation, it starts out
// with this.originalBox.
this.targetBox = null;
// Make all LayoutBoxes resizable. Update whenever the layout changes.
this.layout.forEachBox(this.makeResizable, this);
this.listenTo(this.layout, 'layoutChanged', () => {
this.layout.forEachBox(this.makeResizable, this);
});
const self = this;
this.boundMouseDown = function(this: HTMLElement, ev: MouseEvent) {
return self.handleMouseDown(ev, this);
};
this.boundMouseMove = this.handleMouseMove.bind(this);
this.boundMouseUp = this.handleMouseUp.bind(this);
G.$(this.rootElem).on('mousedown', '.layout_leaf', this.boundMouseDown);
this.initialMouseDown = false;
this.lastTriggered = 'stop';
this.autoDisposeCallback(() => {
G.$(G.window).off('mouseup', this.boundMouseUp);
G.$(G.window).off('mousemove', this.boundMouseMove);
G.$(this.rootElem).off('mousedown', this.boundMouseDown);
if (!this.layout.isDisposed()) {
this.layout.buildLayout(this.layout.getLayoutSpec(), false);
this.layout.forEachBox(this.unmakeResizable, this);
}
});
}
public triggerUserEditStart() {
assert(this.lastTriggered === 'stop', "UserEditStart triggered twice in succession");
this.lastTriggered = 'start';
// This attribute allows browser tests to tell when an edit is in progress.
this.rootElem.setAttribute('data-useredit', 'start');
this.layout.trigger('layoutUserEditStart');
}
public triggerUserEditStop() {
assert(this.lastTriggered === 'start', "UserEditStop triggered twice in succession");
this.lastTriggered = 'stop';
this.layout.trigger('layoutUserEditStop');
// This attribute allows browser tests to tell when an edit is finished.
this.rootElem.setAttribute('data-useredit', 'stop');
}
public makeResizable(box: LayoutBox) {
// Do not add resizable if:
// Box already resizable, box is not vertically resizable, box is last in it`s group.
if (G.$(box.dom).resizable('instance') || (box.isHBox() && !this.layout.fillWindow) ||
box.isLastChild()) {
return;
}
const helperObj = new HelperBox({box});
const isWidth = box.isVBox();
G.$(box.dom).resizable({
handles: isWidth ? 'e' : 's',
start: this.onResizeStart.bind(this, helperObj, isWidth),
resize: this.onResizeMove.bind(this, helperObj, isWidth),
stop: this.triggerUserEditStop.bind(this)
});
}
public unmakeResizable(box: LayoutBox) {
if (G.$(box.dom).resizable("instance")) {
// Resizable widget is set for this box.
G.$(box.dom).resizable('destroy');
}
}
public onResizeStart(helperObj: HelperBox, isWidth: boolean, event: MouseEvent, ui: JqueryUI) {
this.triggerUserEditStart();
const size = isWidth ? ui.originalSize.width : ui.originalSize.height;
helperObj.scalePerFlexUnit = size / (helperObj.box.flexSize() || 1);
const allSiblings = helperObj.box.parentBox()!.childBoxes.peek();
const index = allSiblings.indexOf(helperObj.box);
helperObj.nextSiblings = allSiblings.slice(index + 1);
helperObj.origNextSizes = helperObj.nextSiblings.map(function(b) { return b.flexSize(); });
helperObj.origSize = helperObj.box.flexSize();
helperObj.sumPrev = allSiblings.slice(0, index).reduce(adder, 0);
helperObj.sumAll = allSiblings.reduce(adder, 0);
helperObj.sumNext = helperObj.sumAll - helperObj.sumPrev;
}
public onResizeMove(helperObj: HelperBox, isWidth: boolean, event: MouseEvent, ui: JqueryUI) {
const sizePx = isWidth ? ui.size.width : ui.size.height;
let newSize = sizePx / helperObj.scalePerFlexUnit;
// We need some amount of snapping to make it easier to align boxes. The way we'll do it is to
// adjust flexSize of the box being resized and all following boxes so that boundaries end up at
// multiples of fullSize / NumSteps.
newSize = snap(newSize, helperObj.sumPrev, helperObj.sumAll);
const siblingsFactor = (helperObj.sumNext - newSize) / (helperObj.sumNext - helperObj.origSize);
let sumPrev = helperObj.sumPrev + newSize;
const newSizes: number[] = [];
helperObj.origNextSizes.forEach(function(size) {
const s = snap(size * siblingsFactor, sumPrev, helperObj.sumAll);
sumPrev += s;
newSizes.push(s);
});
if (newSize <= 0 || newSizes.some(size => size <= 0)) {
return; // This isn't an acceptable position.
}
if (newSize !== helperObj.box.flexSize.peek()) {
helperObj.box.flexSize(newSize);
helperObj.nextSiblings.forEach(function(b, i) {
b.flexSize(newSizes[i]);
});
this.layout.trigger('layoutResized');
}
}
public handleMouseDown(event: MouseEvent, elem: HTMLElement) {
const target = (event.target as HTMLElement);
if (event.button !== 0 || target?.classList.contains('ui-resizable-handle')) {
return;
}
if (target?.classList.contains('layout_grabbable')) {
this.initialMouseDown = true;
this.originalBox = utils.domData.get(elem, 'layoutBox');
assert(this.originalBox, "MouseDown on element without an associated layoutBox");
G.$(G.window).on('mousemove', this.boundMouseMove);
G.$(G.window).on('mouseup', this.boundMouseUp);
return false;
}
}
// Exposed for tests
public dragInNewBox(event: MouseEvent, leafId: number) {
const box = this.layout.buildLayoutBox({leaf: leafId});
// Place this box into a measuring div.
this.measuringBox.appendChild(box.getDom());
this.handleMouseDown(event, box.dom!);
}
public startDragBox(event: MouseEvent, box: LayoutBox) {
this.triggerUserEditStart();
this.targetBox = box;
this.floater.onInitialMouseMove(event, box);
}
public handleMouseUp(event: MouseEvent) {
G.$(G.window).off('mousemove', this.boundMouseMove);
G.$(G.window).off('mouseup', this.boundMouseUp);
if (this.initialMouseDown) {
this.initialMouseDown = false;
return;
}
this.targetBox!.takeLeafFrom(this.floater);
if (this.dropTargeter.activeTarget) {
this.dropTargeter.accelerateInsertion();
} else {
resizeLayoutBox(this.targetBox!, 'reset');
}
this.dropTargeter.removeTargetHints();
this.dropOverlay.detach();
this.transitionPromise.finally(() => {
this.floater.onMouseUp();
resizeLayoutBox(this.targetBox!, 'reset');
this.targetBox = this.originalBox = null;
emptyNode(this.measuringBox);
this.triggerUserEditStop();
});
}
public removeContainingBox(elem: HTMLElement) {
const box = this.layout.getContainingBox(elem);
if (box && !box.isDomDetached()) {
this.triggerUserEditStart();
this.targetBox = box;
const rect = box.dom.getBoundingClientRect();
box.leafId('empty');
box.leafContent(dom('div.layout_editor_empty_space',
koDom.style('min-height', rect.height + 'px')
));
this.onInsertBox(noop).catch(noop);
this.triggerUserEditStop();
}
}
public handleMouseMove(event: MouseEvent) {
// Make sure the grabbed box still exists
if (!this.originalBox || this.originalBox?.isDisposed()) {
return;
}
if (this.initialMouseDown) {
this.initialMouseDown = false;
this.startDragBox(event, this.originalBox);
}
this.floater.onMouseMove(event);
if (this.transitionPromise.isPending()) {
// Don't attempt to do any repositioning while another reposition is happening.
return;
}
// Handle dragging to trash.
if (dom.findAncestor(event.target, null, '.layout_trash')) {
const isTrashed = this.targetBox && this.targetBox.isDomDetached();
if (!this.trashDelay.isPending() && !isTrashed) {
// To "trash" a box, we call onInsertBox with noop for the inserter function. The new box
// will still be created, just not attached to anything.
this.trashDelay.schedule(100, this.onInsertBox, this, noop);
}
return;
}
this.trashDelay.cancel();
// See if we are over a layout_leaf, and that the leaf is in the same layout as the dragged
// element. If so, we are dealing with repositioning.
const elem = dom.findAncestor(event.target, this.rootElem, '.' + this.layout.leafId);
if (elem) {
const hoverBox = utils.domData.get(elem, 'layoutBox');
this.dropOverlay.attach(elem);
const affinity = this.dropOverlay.getAffinity(event);
this.dropTargeter.updateTargetHints(hoverBox, affinity, this.dropOverlay, this.targetBox!);
} else if (!dom.findAncestor(event.target, this.rootElem, '.layout_editor_drop_target')) {
this.dropTargeter.removeTargetHints();
}
}
public async onInsertBox(inserterFunc: (box: LayoutBox) => void) {
// Create a new LayoutBox, and insert it using inserterFunc.
// Shrink prevTargetBox to 0. Create a new target box, initially shrunk, and grow it.
const prevTargetBox = this.targetBox!;
this.targetBox = LayoutBox.create(this.layout);
this.targetBox.takeLeafFrom(prevTargetBox);
this.targetBox.flexSize(prevTargetBox.flexSize());
// Sizing boxes vertically requires extra care that the sum of values doesn't change.
this.targetBox.getDom(); // Make sure its dom is created.
//console.log("onInsertBox %s -> %s", prevTargetBox, this.targetBox);
let transitionPromiseResolve!: () => void;
this.transitionPromise = new Promise(function(resolve, reject) {
transitionPromiseResolve = resolve;
});
inserterFunc(this.targetBox);
const prevRect = prevTargetBox.dom!.getBoundingClientRect();
// Set previous box size to 0 for accurate measurement of new target box
const prevFlexGrow = prevTargetBox.dom!.style.flexGrow;
prevTargetBox.dom!.style.flexGrow = '0';
const targetRect = this.targetBox.dom!.getBoundingClientRect();
prevTargetBox.dom!.style.flexGrow = prevFlexGrow;
await Promise.all([
resizeLayoutBoxSmoothly(prevTargetBox, prevRect, 'collapse'),
resizeLayoutBoxSmoothly(this.targetBox, 'collapse', targetRect),
]);
prevTargetBox.dispose();
if (this.targetBox) {
resizeLayoutBox(this.targetBox, 'reset');
this.dropOverlay.attach(this.targetBox.dom!);
}
transitionPromiseResolve();
this.layout.trigger('layoutResized');
}
}
extend(LayoutEditor.prototype, BackboneEvents);
//----------------------------------------------------------------------
/**
* When the user hovers near the edge of a box, we call the direction the "affinity", and it
* indicates where an insertion is to happen. Affinities are represented by numbers 0 - 3. The
* functions below distinguish top-down vs left-right, and top/left vs down/right.
*/
//const AFFINITY_NAMES = { 0: 'TOP', 1: 'DOWN', 2: 'LEFT', 3: 'RIGHT' };
function isAffinityUpDown(affinity: number): boolean {
return (affinity >> 1) === 0;
}
function isAffinityAfter(affinity: number): boolean {
return (affinity & 1) === 1;
}
function getFrac(distance: number, max: number): number {
return distance < max ? distance / max : Infinity;
}
// We'll snap to 1/NumSteps of total size. The choice of 60 allows many evenly-sized layouts.
const NumSteps = 60;
function round(value: number, multipleOf: number) {
return Math.round(value / multipleOf) * multipleOf;
}
function snap(flexSize: number, sumPrev: number, sumAll: number) {
const endEdge = round(sumPrev + flexSize, sumAll / NumSteps);
return Math.min(endEdge, sumAll) - sumPrev;
}
/**
* Resizes the given LayoutBox to transition it when it's supposed to expand or collapse. It only
* affects the height for HBoxes, and only the width for VBoxes. For rows, we use an explicit
* height. For columns we rely on 'flex-grow' property.
* A rectangle object: set the relevant style according to the values there.
* 'reset': unset the relevant style, to revert to the values associated with CSS classes.
* 'collapse': collapse to empty size.
* 'current': set and explicit value for the relevant style, which is needed for transitions.
*/
function resizeLayoutBox(layoutBox: LayoutBox, sizeRect: string|DOMRect) {
const reset = (sizeRect === 'reset');
const collapse = (sizeRect === 'collapse');
if (sizeRect === 'current') {
sizeRect = layoutBox.dom!.getBoundingClientRect();
}
if (layoutBox.isHBox()) {
layoutBox.dom!.style.height = (reset ? '' : (collapse ? '0px' : (sizeRect as DOMRect).height + 'px'));
} else {
layoutBox.dom!.style.width = (reset ? '' : (collapse ? '0px' : (sizeRect as DOMRect).width + 'px'));
}
layoutBox.dom!.style.opacity = collapse ? '0.0' : '1.0';
}
function rectDesc(rect: string|DOMRect) {
return (typeof rect === 'string') ? rect :
Math.floor(rect.width) + "x" + Math.floor(rect.height);
}
/**
* Resizes the given LayoutBox smoothly from starting to ending position, where startRect and
* endRect are one of the values documented in 'resizeLayoutBox'.
*/
function resizeLayoutBoxSmoothly(layoutBox: LayoutBox, startRect: string|DOMRect, endRect: string|DOMRect) {
if (layoutBox.isDomDetached()) {
return Promise.resolve();
}
const prevFlexGrow = layoutBox.dom!.style.flexGrow;
layoutBox.dom!.style.flexGrow = '0';
resizeLayoutBox(layoutBox, startRect);
// Force the layout engine to compute the current state of the layoutBox.dom element before
// applying the transition. This follows the recommendation here, and seems to work:
// https://timtaubert.de/blog/2012/09/css-transitions-for-dynamically-created-dom-elements/
pick(G.window.getComputedStyle(layoutBox.dom), 'height', 'width');
// Start the transition.
layoutBox.dom!.classList.add('layout_editor_resize_transition');
return new Promise(function(resolve, reject) {
dom.once(layoutBox.dom, 'transitionend', function() { resolve(); });
resizeLayoutBox(layoutBox, endRect);
})
.timeout(600) // Transitions are only 400ms long, so complain if nothing happened for longer.
.catch(Promise.TimeoutError, function() {
console.error("LayoutEditor.resizeLayoutBoxSmoothly %s %s->%s: transition didn't run",
layoutBox, rectDesc(startRect), rectDesc(endRect));
// We keep going. It should look like something's wrong and jumpy, but it should still be
// usable and not cause errors elsewhere.
})
.finally(function() {
layoutBox.dom!.classList.remove('layout_editor_resize_transition');
layoutBox.dom!.style.flexGrow = prevFlexGrow;
});
}
function adder(sum: number, box: LayoutBox) {
return sum + box.flexSize.peek();
}