scratch-blocks/core/gesture.js
2018-10-24 11:42:42 -04:00

1011 lines
30 KiB
JavaScript

/**
* @license
* Visual Blocks Editor
*
* Copyright 2017 Google Inc.
* https://developers.google.com/blockly/
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @fileoverview The class representing an in-progress gesture, usually a drag
* or a tap.
* @author fenichel@google.com (Rachel Fenichel)
*/
'use strict';
goog.provide('Blockly.Gesture');
goog.require('Blockly.BlockAnimations');
goog.require('Blockly.BlockDragger');
goog.require('Blockly.BubbleDragger');
goog.require('Blockly.constants');
goog.require('Blockly.Events.Ui');
goog.require('Blockly.FlyoutDragger');
goog.require('Blockly.scratchBlocksUtils');
goog.require('Blockly.Tooltip');
goog.require('Blockly.Touch');
goog.require('Blockly.WorkspaceDragger');
goog.require('goog.asserts');
goog.require('goog.math.Coordinate');
/*
* Note: In this file "start" refers to touchstart, mousedown, and pointerstart
* events. "End" refers to touchend, mouseup, and pointerend events.
*/
// TODO: Consider touchcancel/pointercancel.
/**
* Class for one gesture.
* @param {!Event} e The event that kicked off this gesture.
* @param {!Blockly.WorkspaceSvg} creatorWorkspace The workspace that created
* this gesture and has a reference to it.
* @constructor
*/
Blockly.Gesture = function(e, creatorWorkspace) {
/**
* The position of the mouse when the gesture started. Units are css pixels,
* with (0, 0) at the top left of the browser window (mouseEvent clientX/Y).
* @type {goog.math.Coordinate}
*/
this.mouseDownXY_ = null;
/**
* How far the mouse has moved during this drag, in pixel units.
* (0, 0) is at this.mouseDownXY_.
* @type {goog.math.Coordinate}
* @private
*/
this.currentDragDeltaXY_ = null;
/**
* The bubble that the gesture started on, or null if it did not start on a
* bubble.
* @type {Blockly.Bubble}
* @private
*/
this.startBubble_ = null;
/**
* The field that the gesture started on, or null if it did not start on a
* field.
* @type {Blockly.Field}
* @private
*/
this.startField_ = null;
/**
* The block that the gesture started on, or null if it did not start on a
* block.
* @type {Blockly.BlockSvg}
* @private
*/
this.startBlock_ = null;
/**
* The block that this gesture targets. If the gesture started on a
* shadow block, this is the first non-shadow parent of the block. If the
* gesture started in the flyout, this is the root block of the block group
* that was clicked or dragged.
* @type {Blockly.BlockSvg}
* @private
*/
this.targetBlock_ = null;
/**
* The workspace that the gesture started on. There may be multiple
* workspaces on a page; this is more accurate than using
* Blockly.getMainWorkspace().
* @type {Blockly.WorkspaceSvg}
* @private
*/
this.startWorkspace_ = null;
/**
* The workspace that created this gesture. This workspace keeps a reference
* to the gesture, which will need to be cleared at deletion.
* This may be different from the start workspace. For instance, a flyout is
* a workspace, but its parent workspace manages gestures for it.
* @type {Blockly.WorkspaceSvg}
* @private
*/
this.creatorWorkspace_ = creatorWorkspace;
/**
* Whether the pointer has at any point moved out of the drag radius.
* A gesture that exceeds the drag radius is a drag even if it ends exactly at
* its start point.
* @type {boolean}
* @private
*/
this.hasExceededDragRadius_ = false;
/**
* Whether the workspace is currently being dragged.
* @type {boolean}
* @private
*/
this.isDraggingWorkspace_ = false;
/**
* Whether the block is currently being dragged.
* @type {boolean}
* @private
*/
this.isDraggingBlock_ = false;
/**
* Whether the bubble is currently being dragged.
* @type {boolean}
* @private
*/
this.isDraggingBubble_ = false;
/**
* The event that most recently updated this gesture.
* @type {!Event}
* @private
*/
this.mostRecentEvent_ = e;
/**
* A handle to use to unbind a mouse move listener at the end of a drag.
* Opaque data returned from Blockly.bindEventWithChecks_.
* @type {Array.<!Array>}
* @private
*/
this.onMoveWrapper_ = null;
/**
* A handle to use to unbind a mouse up listener at the end of a drag.
* Opaque data returned from Blockly.bindEventWithChecks_.
* @type {Array.<!Array>}
* @private
*/
this.onUpWrapper_ = null;
/**
* The object tracking a bubble drag, or null if none is in progress.
* @type {Blockly.BubbleDragger}
* @private
*/
this.bubbleDragger_ = null;
/**
* The object tracking a block drag, or null if none is in progress.
* @type {Blockly.BlockDragger}
* @private
*/
this.blockDragger_ = null;
/**
* The object tracking a workspace or flyout workspace drag, or null if none
* is in progress.
* @type {Blockly.WorkspaceDragger}
* @private
*/
this.workspaceDragger_ = null;
/**
* The flyout a gesture started in, if any.
* @type {Blockly.Flyout}
* @private
*/
this.flyout_ = null;
/**
* Boolean for sanity-checking that some code is only called once.
* @type {boolean}
* @private
*/
this.calledUpdateIsDragging_ = false;
/**
* Boolean for sanity-checking that some code is only called once.
* @type {boolean}
* @private
*/
this.hasStarted_ = false;
/**
* Boolean used internally to break a cycle in disposal.
* @type {boolean}
* @private
*/
this.isEnding_ = false;
/**
* True if dragging from the target block should duplicate the target block
* and drag the duplicate instead. This has a lot of side effects.
* @type {boolean}
* @private
*/
this.shouldDuplicateOnDrag_ = false;
};
/**
* Sever all links from this object.
* @package
*/
Blockly.Gesture.prototype.dispose = function() {
Blockly.Touch.clearTouchIdentifier();
Blockly.Tooltip.unblock();
// Clear the owner's reference to this gesture.
this.creatorWorkspace_.clearGesture();
if (this.onMoveWrapper_) {
Blockly.unbindEvent_(this.onMoveWrapper_);
}
if (this.onUpWrapper_) {
Blockly.unbindEvent_(this.onUpWrapper_);
}
this.startField_ = null;
this.startBlock_ = null;
this.targetBlock_ = null;
this.startWorkspace_ = null;
this.flyout_ = null;
if (this.blockDragger_) {
this.blockDragger_.dispose();
this.blockDragger_ = null;
}
if (this.workspaceDragger_) {
this.workspaceDragger_.dispose();
this.workspaceDragger_ = null;
}
if (this.bubbleDragger_) {
this.bubbleDragger_.dispose();
this.bubbleDragger_ = null;
}
};
/**
* Update internal state based on an event.
* @param {!Event} e The most recent mouse or touch event.
* @private
*/
Blockly.Gesture.prototype.updateFromEvent_ = function(e) {
var currentXY = new goog.math.Coordinate(e.clientX, e.clientY);
var changed = this.updateDragDelta_(currentXY);
// Exceeded the drag radius for the first time.
if (changed) {
this.updateIsDragging_();
Blockly.longStop_();
}
this.mostRecentEvent_ = e;
};
/**
* DO MATH to set currentDragDeltaXY_ based on the most recent mouse position.
* @param {!goog.math.Coordinate} currentXY The most recent mouse/pointer
* position, in pixel units, with (0, 0) at the window's top left corner.
* @return {boolean} True if the drag just exceeded the drag radius for the
* first time.
* @private
*/
Blockly.Gesture.prototype.updateDragDelta_ = function(currentXY) {
this.currentDragDeltaXY_ = goog.math.Coordinate.difference(currentXY,
this.mouseDownXY_);
if (!this.hasExceededDragRadius_) {
var currentDragDelta = goog.math.Coordinate.magnitude(
this.currentDragDeltaXY_);
// The flyout has a different drag radius from the rest of Blockly.
var limitRadius = this.flyout_ ? Blockly.FLYOUT_DRAG_RADIUS :
Blockly.DRAG_RADIUS;
this.hasExceededDragRadius_ = currentDragDelta > limitRadius;
return this.hasExceededDragRadius_;
}
return false;
};
/**
* Update this gesture to record whether a block is being dragged from the
* flyout.
* This function should be called on a mouse/touch move event the first time the
* drag radius is exceeded. It should be called no more than once per gesture.
* If a block should be dragged from the flyout this function creates the new
* block on the main workspace and updates targetBlock_ and startWorkspace_.
* @return {boolean} True if a block is being dragged from the flyout.
* @private
*/
Blockly.Gesture.prototype.updateIsDraggingFromFlyout_ = function() {
// Disabled blocks may not be dragged from the flyout.
if (this.targetBlock_.disabled) {
return false;
}
if (!this.flyout_.isScrollable() ||
this.flyout_.isDragTowardWorkspace(this.currentDragDeltaXY_)) {
this.startWorkspace_ = this.flyout_.targetWorkspace_;
this.startWorkspace_.updateScreenCalculationsIfScrolled();
// Start the event group now, so that the same event group is used for block
// creation and block dragging.
if (!Blockly.Events.getGroup()) {
Blockly.Events.setGroup(true);
}
// The start block is no longer relevant, because this is a drag.
this.startBlock_ = null;
this.targetBlock_ = this.flyout_.createBlock(this.targetBlock_);
this.targetBlock_.select();
return true;
}
return false;
};
/**
* Update this gesture to record whether a bubble is being dragged.
* This function should be called on a mouse/touch move event the first time the
* drag radius is exceeded. It should be called no more than once per gesture.
* If a bubble should be dragged this function creates the necessary
* BubbleDragger and starts the drag.
* @return {boolean} true if a bubble is being dragged.
* @private
*/
Blockly.Gesture.prototype.updateIsDraggingBubble_ = function() {
if (!this.startBubble_) {
return false;
}
this.isDraggingBubble_ = true;
this.startDraggingBubble_();
return true;
};
/**
* Update this gesture to record whether a block is being dragged.
* This function should be called on a mouse/touch move event the first time the
* drag radius is exceeded. It should be called no more than once per gesture.
* If a block should be dragged, either from the flyout or in the workspace,
* this function creates the necessary BlockDragger and starts the drag.
* @return {boolean} true if a block is being dragged.
* @private
*/
Blockly.Gesture.prototype.updateIsDraggingBlock_ = function() {
if (!this.targetBlock_) {
return false;
}
if (this.flyout_) {
this.isDraggingBlock_ = this.updateIsDraggingFromFlyout_();
} else if (this.targetBlock_.isMovable() || this.shouldDuplicateOnDrag_){
this.isDraggingBlock_ = true;
}
if (this.isDraggingBlock_) {
this.startDraggingBlock_();
return true;
}
return false;
};
/**
* Update this gesture to record whether a workspace is being dragged.
* This function should be called on a mouse/touch move event the first time the
* drag radius is exceeded. It should be called no more than once per gesture.
* If a workspace is being dragged this function creates the necessary
* WorkspaceDragger or FlyoutDragger and starts the drag.
* @private
*/
Blockly.Gesture.prototype.updateIsDraggingWorkspace_ = function() {
var wsMovable = this.flyout_ ? this.flyout_.isScrollable() :
this.startWorkspace_ && this.startWorkspace_.isDraggable();
if (!wsMovable) {
return;
}
if (this.flyout_) {
this.workspaceDragger_ = new Blockly.FlyoutDragger(this.flyout_);
} else {
this.workspaceDragger_ = new Blockly.WorkspaceDragger(this.startWorkspace_);
}
this.isDraggingWorkspace_ = true;
this.workspaceDragger_.startDrag();
};
/**
* Update this gesture to record whether anything is being dragged.
* This function should be called on a mouse/touch move event the first time the
* drag radius is exceeded. It should be called no more than once per gesture.
* @private
*/
Blockly.Gesture.prototype.updateIsDragging_ = function() {
// Sanity check.
goog.asserts.assert(!this.calledUpdateIsDragging_,
'updateIsDragging_ should only be called once per gesture.');
this.calledUpdateIsDragging_ = true;
// First check if it was a bubble drag. Bubbles always sit on top of blocks.
if (this.updateIsDraggingBubble_()) {
return;
}
// Then check if it was a block drag.
if (this.updateIsDraggingBlock_()) {
return;
}
// Then check if it's a workspace drag.
this.updateIsDraggingWorkspace_();
};
/**
* Create a block dragger and start dragging the selected block.
* @private
*/
Blockly.Gesture.prototype.startDraggingBlock_ = function() {
if (this.shouldDuplicateOnDrag_) {
this.duplicateOnDrag_();
}
this.blockDragger_ = new Blockly.BlockDragger(this.targetBlock_,
this.startWorkspace_);
this.blockDragger_.startBlockDrag(this.currentDragDeltaXY_);
this.blockDragger_.dragBlock(this.mostRecentEvent_,
this.currentDragDeltaXY_);
};
/**
* Create a bubble dragger and start dragging the selected bubble.
* TODO (fenichel): Possibly combine this and startDraggingBlock_.
* @private
*/
Blockly.Gesture.prototype.startDraggingBubble_ = function() {
this.bubbleDragger_ = new Blockly.BubbleDragger(this.startBubble_,
this.startWorkspace_);
this.bubbleDragger_.startBubbleDrag();
this.bubbleDragger_.dragBubble(this.mostRecentEvent_,
this.currentDragDeltaXY_);
};
/**
* Start a gesture: update the workspace to indicate that a gesture is in
* progress and bind mousemove and mouseup handlers.
* @param {!Event} e A mouse down or touch start event.
* @package
*/
Blockly.Gesture.prototype.doStart = function(e) {
if (Blockly.utils.isTargetInput(e)) {
this.cancel();
return;
}
this.hasStarted_ = true;
Blockly.BlockAnimations.disconnectUiStop();
this.startWorkspace_.updateScreenCalculationsIfScrolled();
if (this.startWorkspace_.isMutator) {
// Mutator's coordinate system could be out of date because the bubble was
// dragged, the block was moved, the parent workspace zoomed, etc.
this.startWorkspace_.resize();
}
this.startWorkspace_.markFocused();
this.mostRecentEvent_ = e;
// Hide chaff also hides the flyout, so don't do it if the click is in a flyout.
Blockly.hideChaff(!!this.flyout_);
Blockly.Tooltip.block();
if (this.targetBlock_) {
this.targetBlock_.select();
}
if (Blockly.utils.isRightButton(e)) {
this.handleRightClick(e);
return;
}
if (goog.string.caseInsensitiveEquals(e.type, 'touchstart')) {
Blockly.longStart_(e, this);
}
this.mouseDownXY_ = new goog.math.Coordinate(e.clientX, e.clientY);
this.currentDragDeltaXY_ = new goog.math.Coordinate(0, 0);
this.bindMouseEvents(e);
};
/**
* Bind gesture events.
* @param {!Event} e A mouse down or touch start event.
* @package
*/
Blockly.Gesture.prototype.bindMouseEvents = function(e) {
this.onMoveWrapper_ = Blockly.bindEventWithChecks_(
document, 'mousemove', null, this.handleMove.bind(this));
this.onUpWrapper_ = Blockly.bindEventWithChecks_(
document, 'mouseup', null, this.handleUp.bind(this));
e.preventDefault();
e.stopPropagation();
};
/**
* Handle a mouse move or touch move event.
* @param {!Event} e A mouse move or touch move event.
* @package
*/
Blockly.Gesture.prototype.handleMove = function(e) {
var stopPropagation = true;
this.updateFromEvent_(e);
if (this.isDraggingWorkspace_) {
this.workspaceDragger_.drag(this.currentDragDeltaXY_);
} else if (this.isDraggingBlock_) {
if (this.blockDragger_.dragBlock(
this.mostRecentEvent_, this.currentDragDeltaXY_)) {
stopPropagation = false;
}
} else if (this.isDraggingBubble_) {
this.bubbleDragger_.dragBubble(this.mostRecentEvent_,
this.currentDragDeltaXY_);
}
if (stopPropagation) {
e.preventDefault();
e.stopPropagation();
}
};
/**
* Handle a mouse up or touch end event.
* @param {!Event} e A mouse up or touch end event.
* @package
*/
Blockly.Gesture.prototype.handleUp = function(e) {
this.updateFromEvent_(e);
Blockly.longStop_();
if (this.isEnding_) {
return;
}
this.isEnding_ = true;
// The ordering of these checks is important: drags have higher priority than
// clicks. Fields have higher priority than blocks; blocks have higher
// priority than workspaces.
// The ordering within drags does not matter, because the three types of
// dragging are exclusive.
if (this.isDraggingBubble_) {
this.bubbleDragger_.endBubbleDrag(e, this.currentDragDeltaXY_);
} else if (this.isDraggingBlock_) {
this.blockDragger_.endBlockDrag(e, this.currentDragDeltaXY_);
} else if (this.isDraggingWorkspace_) {
this.workspaceDragger_.endDrag(this.currentDragDeltaXY_);
} else if (this.isBubbleClick_()) {
// Bubbles are in front of all fields and blocks.
this.doBubbleClick_();
} else if (this.isFieldClick_()) {
this.doFieldClick_();
} else if (this.isBlockClick_()) {
this.doBlockClick_();
} else if (this.isWorkspaceClick_()) {
this.doWorkspaceClick_();
}
e.preventDefault();
e.stopPropagation();
this.dispose();
};
/**
* Cancel an in-progress gesture. If a workspace or block drag is in progress,
* end the drag at the most recent location.
* @package
*/
Blockly.Gesture.prototype.cancel = function() {
// Disposing of a block cancels in-progress drags, but dragging to a delete
// area disposes of a block and leads to recursive disposal. Break that cycle.
if (this.isEnding_) {
console.log('Trying to cancel a gesture recursively.');
return;
}
this.isEnding_ = true;
Blockly.longStop_();
if (this.isDraggingBubble_) {
this.bubbleDragger_.endBubbleDrag(this.mostRecentEvent_,
this.currentDragDeltaXY_);
} else if (this.isDraggingBlock_) {
this.blockDragger_.endBlockDrag(this.mostRecentEvent_,
this.currentDragDeltaXY_);
} else if (this.isDraggingWorkspace_) {
this.workspaceDragger_.endDrag(this.currentDragDeltaXY_);
}
this.dispose();
};
/**
* Handle a real or faked right-click event by showing a context menu.
* @param {!Event} e A mouse move or touch move event.
* @package
*/
Blockly.Gesture.prototype.handleRightClick = function(e) {
if (this.targetBlock_) {
this.bringBlockToFront_();
Blockly.hideChaff(this.flyout_);
this.targetBlock_.showContextMenu_(e);
} else if (this.startBubble_) {
this.startBubble_.showContextMenu_(e);
} else if (this.startWorkspace_ && !this.flyout_) {
Blockly.hideChaff();
this.startWorkspace_.showContextMenu_(e);
}
// TODO: Handle right-click on a bubble.
e.preventDefault();
e.stopPropagation();
this.dispose();
};
/**
* Handle a mousedown/touchstart event on a workspace.
* @param {!Event} e A mouse down or touch start event.
* @param {!Blockly.Workspace} ws The workspace the event hit.
* @package
*/
Blockly.Gesture.prototype.handleWsStart = function(e, ws) {
goog.asserts.assert(!this.hasStarted_,
'Tried to call gesture.handleWsStart, but the gesture had already been ' +
'started.');
this.setStartWorkspace_(ws);
this.mostRecentEvent_ = e;
this.doStart(e);
};
/**
* Handle a mousedown/touchstart event on a flyout.
* @param {!Event} e A mouse down or touch start event.
* @param {!Blockly.Flyout} flyout The flyout the event hit.
* @package
*/
Blockly.Gesture.prototype.handleFlyoutStart = function(e, flyout) {
goog.asserts.assert(!this.hasStarted_,
'Tried to call gesture.handleFlyoutStart, but the gesture had already ' +
'been started.');
this.setStartFlyout_(flyout);
this.handleWsStart(e, flyout.getWorkspace());
};
/**
* Handle a mousedown/touchstart event on a block.
* @param {!Event} e A mouse down or touch start event.
* @param {!Blockly.BlockSvg} block The block the event hit.
* @package
*/
Blockly.Gesture.prototype.handleBlockStart = function(e, block) {
goog.asserts.assert(!this.hasStarted_,
'Tried to call gesture.handleBlockStart, but the gesture had already ' +
'been started.');
this.setStartBlock(block);
this.mostRecentEvent_ = e;
};
/**
* Handle a mousedown/touchstart event on a bubble.
* @param {!Event} e A mouse down or touch start event.
* @param {!Blockly.Bubble} bubble The bubble the event hit.
* @package
*/
Blockly.Gesture.prototype.handleBubbleStart = function(e, bubble) {
goog.asserts.assert(!this.hasStarted_,
'Tried to call gesture.handleBubbleStart, but the gesture had already ' +
'been started.');
this.setStartBubble(bubble);
this.mostRecentEvent_ = e;
};
/* Begin functions defining what actions to take to execute clicks on each type
* of target. Any developer wanting to add behaviour on clicks should modify
* only this code. */
/**
* Execute a bubble click.
* @private
*/
Blockly.Gesture.prototype.doBubbleClick_ = function() {
// TODO (github.com/google/blockly/issues/1673): Consistent handling of single
// clicks.
this.startBubble_.setFocus && this.startBubble_.setFocus();
this.startBubble_.select && this.startBubble_.select();
};
/**
* Execute a field click.
* @private
*/
Blockly.Gesture.prototype.doFieldClick_ = function() {
this.startField_.showEditor_();
this.bringBlockToFront_();
};
/**
* Execute a block click.
* @private
*/
Blockly.Gesture.prototype.doBlockClick_ = function() {
// Block click in an autoclosing flyout.
if (this.flyout_ && this.flyout_.autoClose) {
if (!this.targetBlock_.disabled) {
if (!Blockly.Events.getGroup()) {
Blockly.Events.setGroup(true);
}
var newBlock = this.flyout_.createBlock(this.targetBlock_);
newBlock.scheduleSnapAndBump();
}
} else {
// A field is being edited if either the WidgetDiv or DropDownDiv is currently open.
// If a field is being edited, don't fire any click events.
var fieldEditing = Blockly.WidgetDiv.isVisible() || Blockly.DropDownDiv.isVisible();
if (!fieldEditing) {
Blockly.Events.fire(
new Blockly.Events.Ui(this.startBlock_, 'click', undefined, undefined));
// Scratch-specific: also fire a "stack click" event for this stack.
// This is used to toggle the stack when any block in the stack is clicked.
var rootBlock = this.startBlock_.getRootBlock();
Blockly.Events.fire(
new Blockly.Events.Ui(rootBlock, 'stackclick', undefined, undefined));
}
}
this.bringBlockToFront_();
Blockly.Events.setGroup(false);
};
/**
* Execute a workspace click.
* @private
*/
Blockly.Gesture.prototype.doWorkspaceClick_ = function() {
if (Blockly.selected) {
Blockly.selected.unselect();
}
};
/* End functions defining what actions to take to execute clicks on each type
* of target. */
// TODO (fenichel): Move bubbles to the front.
/**
* Move the dragged/clicked block to the front of the workspace so that it is
* not occluded by other blocks.
* @private
*/
Blockly.Gesture.prototype.bringBlockToFront_ = function() {
// Blocks in the flyout don't overlap, so skip the work.
if (this.targetBlock_ && !this.flyout_) {
this.targetBlock_.bringToFront();
}
};
/* Begin functions for populating a gesture at mouse down. */
/**
* Record the field that a gesture started on.
* @param {Blockly.Field} field The field the gesture started on.
* @package
*/
Blockly.Gesture.prototype.setStartField = function(field) {
goog.asserts.assert(!this.hasStarted_,
'Tried to call gesture.setStartField, but the gesture had already been ' +
'started.');
if (!this.startField_) {
this.startField_ = field;
}
};
/**
* Record the bubble that a gesture started on
* @param {Blockly.Bubble} bubble The bubble the gesture started on.
* @package
*/
Blockly.Gesture.prototype.setStartBubble = function(bubble) {
if (!this.startBubble_) {
this.startBubble_ = bubble;
}
};
/**
* Record the block that a gesture started on, and set the target block
* appropriately.
* @param {Blockly.BlockSvg} block The block the gesture started on.
* @package
*/
Blockly.Gesture.prototype.setStartBlock = function(block) {
// If the gesture already went through a bubble, don't set the start block.
if (!this.startBlock_ && !this.startBubble_) {
this.startBlock_ = block;
this.shouldDuplicateOnDrag_ =
Blockly.scratchBlocksUtils.isShadowArgumentReporter(block);
if (block.isInFlyout && block != block.getRootBlock()) {
this.setTargetBlock_(block.getRootBlock());
} else {
this.setTargetBlock_(block);
}
}
};
/**
* Record the block that a gesture targets, meaning the block that will be
* dragged if this turns into a drag. If this block is a shadow, that will be
* its first non-shadow parent.
* @param {Blockly.BlockSvg} block The block the gesture targets.
* @private
*/
Blockly.Gesture.prototype.setTargetBlock_ = function(block) {
if (block.isShadow() && !this.shouldDuplicateOnDrag_) {
this.setTargetBlock_(block.getParent());
} else {
this.targetBlock_ = block;
}
};
/**
* Record the workspace that a gesture started on.
* @param {Blockly.WorkspaceSvg} ws The workspace the gesture started on.
* @private
*/
Blockly.Gesture.prototype.setStartWorkspace_ = function(ws) {
if (!this.startWorkspace_) {
this.startWorkspace_ = ws;
}
};
/**
* Record the flyout that a gesture started on.
* @param {Blockly.Flyout} flyout The flyout the gesture started on.
* @private
*/
Blockly.Gesture.prototype.setStartFlyout_ = function(flyout) {
if (!this.flyout_) {
this.flyout_ = flyout;
}
};
/* End functions for populating a gesture at mouse down. */
/* Begin helper functions defining types of clicks. Any developer wanting
* to change the definition of a click should modify only this code. */
/**
* Whether this gesture is a click on a bubble. This should only be called when
* ending a gesture (mouse up, touch end).
* @return {boolean} whether this gesture was a click on a bubble.
* @private
*/
Blockly.Gesture.prototype.isBubbleClick_ = function() {
// A bubble click starts on a bubble and never escapes the drag radius.
var hasStartBubble = !!this.startBubble_;
return hasStartBubble && !this.hasExceededDragRadius_;
};
/**
* Whether this gesture is a click on a block. This should only be called when
* ending a gesture (mouse up, touch end).
* @return {boolean} whether this gesture was a click on a block.
* @private
*/
Blockly.Gesture.prototype.isBlockClick_ = function() {
// A block click starts on a block, never escapes the drag radius, and is not
// a field click.
var hasStartBlock = !!this.startBlock_;
return hasStartBlock && !this.hasExceededDragRadius_ && !this.isFieldClick_();
};
/**
* Whether this gesture is a click on a field. This should only be called when
* ending a gesture (mouse up, touch end).
* @return {boolean} whether this gesture was a click on a field.
* @private
*/
Blockly.Gesture.prototype.isFieldClick_ = function() {
var fieldEditable = this.startField_ ?
this.startField_.isCurrentlyEditable() : false;
return fieldEditable && !this.hasExceededDragRadius_;
};
/**
* Whether this gesture is a click on a workspace. This should only be called
* when ending a gesture (mouse up, touch end).
* @return {boolean} whether this gesture was a click on a workspace.
* @private
*/
Blockly.Gesture.prototype.isWorkspaceClick_ = function() {
var onlyTouchedWorkspace = !this.startBlock_ && !this.startBubble_ &&
!this.startField_;
return onlyTouchedWorkspace && !this.hasExceededDragRadius_;
};
/* End helper functions defining types of clicks. */
/**
* Whether this gesture is a drag of either a workspace or block.
* This function is called externally to block actions that cannot be taken
* mid-drag (e.g. using the keyboard to delete the selected blocks).
* @return {boolean} true if this gesture is a drag of a workspace or block.
* @package
*/
Blockly.Gesture.prototype.isDragging = function() {
return this.isDraggingWorkspace_ || this.isDraggingBlock_ ||
this.isDraggingBubble_;
};
/**
* Whether this gesture has already been started. In theory every mouse down
* has a corresponding mouse up, but in reality it is possible to lose a
* mouse up, leaving an in-process gesture hanging.
* @return {boolean} whether this gesture was a click on a workspace.
* @package
*/
Blockly.Gesture.prototype.hasStarted = function() {
return this.hasStarted_;
};
/* Scratch-specific */
/**
* Don't even think about using this function before talking to rachel-fenichel.
*
* Force a drag to start without clicking and dragging the block itself. Used
* to attach duplicated blocks to the mouse pointer.
* @param {!Object} fakeEvent An object with the properties needed to start a
* drag, including clientX and clientY.
* @param {!Blockly.BlockSvg} block The block to start dragging.
* @package
*/
Blockly.Gesture.prototype.forceStartBlockDrag = function(fakeEvent, block) {
this.handleBlockStart(fakeEvent, block);
this.handleWsStart(fakeEvent, block.workspace);
this.isDraggingBlock_ = true;
this.hasExceededDragRadius_ = true;
this.startDraggingBlock_();
};
/**
* Duplicate the target block and start dragging the duplicated block.
* This should be done once we are sure that it is a block drag, and no earlier.
* Specifically for argument reporters in custom block defintions.
* @private
*/
Blockly.Gesture.prototype.duplicateOnDrag_ = function() {
var newBlock = null;
Blockly.Events.disable();
try {
// Note: targetBlock_ should have no children. If it has children we would
// need to update shadow block IDs to avoid problems in the VM.
// Resizes will be reenabled at the end of the drag.
this.startWorkspace_.setResizesEnabled(false);
var xmlBlock = Blockly.Xml.blockToDom(this.targetBlock_);
newBlock = Blockly.Xml.domToBlock(xmlBlock, this.startWorkspace_);
// Move the duplicate to original position.
var xy = this.targetBlock_.getRelativeToSurfaceXY();
newBlock.moveBy(xy.x, xy.y);
newBlock.setShadow(false);
} finally {
Blockly.Events.enable();
}
if (!newBlock) {
// Something went wrong.
console.error('Something went wrong while duplicating a block.');
return;
}
if (Blockly.Events.isEnabled()) {
Blockly.Events.fire(new Blockly.Events.BlockCreate(newBlock));
}
newBlock.select();
this.targetBlock_ = newBlock;
};