/**
* @license
* Copyright The Closure Library Authors.
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @fileoverview A palette control. A palette is a grid that the user can
* highlight or select via the keyboard or the mouse.
*
* @see ../demos/palette.html
*/
goog.provide('goog.ui.Palette');
goog.require('goog.asserts');
goog.require('goog.dom');
goog.require('goog.events');
goog.require('goog.events.EventType');
goog.require('goog.events.KeyCodes');
goog.require('goog.math.Size');
goog.require('goog.style');
goog.require('goog.ui.Component');
goog.require('goog.ui.Control');
goog.require('goog.ui.PaletteRenderer');
goog.require('goog.ui.SelectionModel');
goog.requireType('goog.events.BrowserEvent');
goog.requireType('goog.events.Event');
goog.requireType('goog.events.KeyEvent');
goog.requireType('goog.ui.ControlContent');
/**
* A palette is a grid of DOM nodes that the user can highlight or select via
* the keyboard or the mouse. The selection state of the palette is controlled
* an ACTION event. Event listeners may retrieve the selected item using the
* {@link #getSelectedItem} or {@link #getSelectedIndex} method.
*
* Use this class as the base for components like color palettes or emoticon
* pickers. Use {@link #setContent} to set/change the items in the palette
* after construction. See palette.html demo for example usage.
*
* @param {Array<Node>} items Array of DOM nodes to be displayed as items
* in the palette grid (limited to one per cell).
* @param {goog.ui.PaletteRenderer=} opt_renderer Renderer used to render or
* decorate the palette; defaults to {@link goog.ui.PaletteRenderer}.
* @param {goog.dom.DomHelper=} opt_domHelper Optional DOM helper, used for
* document interaction.
* @constructor
* @extends {goog.ui.Control}
*/
goog.ui.Palette = function(items, opt_renderer, opt_domHelper) {
'use strict';
goog.ui.Palette.base(
this, 'constructor', items,
opt_renderer || goog.ui.PaletteRenderer.getInstance(), opt_domHelper);
this.setAutoStates(
goog.ui.Component.State.CHECKED | goog.ui.Component.State.SELECTED |
goog.ui.Component.State.OPENED,
false);
/**
* A fake component for dispatching events on palette cell changes.
* @type {!goog.ui.Palette.CurrentCell_}
* @private
*/
this.currentCellControl_ = new goog.ui.Palette.CurrentCell_();
this.currentCellControl_.setParentEventTarget(this);
/**
* @private {number} The last highlighted index, or -1 if it never had one.
*/
this.lastHighlightedIndex_ = -1;
};
goog.inherits(goog.ui.Palette, goog.ui.Control);
/**
* Events fired by the palette object
* @enum {string}
*/
goog.ui.Palette.EventType = {
AFTER_HIGHLIGHT: goog.events.getUniqueId('afterhighlight')
};
/**
* Palette dimensions (columns x rows). If the number of rows is undefined,
* it is calculated on first use.
* @type {?goog.math.Size}
* @private
*/
goog.ui.Palette.prototype.size_ = null;
/**
* Index of the currently highlighted item (-1 if none).
* @type {number}
* @private
*/
goog.ui.Palette.prototype.highlightedIndex_ = -1;
/**
* Selection model controlling the palette's selection state.
* @type {?goog.ui.SelectionModel}
* @private
*/
goog.ui.Palette.prototype.selectionModel_ = null;
// goog.ui.Component / goog.ui.Control implementation.
/** @override */
goog.ui.Palette.prototype.disposeInternal = function() {
'use strict';
goog.ui.Palette.superClass_.disposeInternal.call(this);
if (this.selectionModel_) {
this.selectionModel_.dispose();
this.selectionModel_ = null;
}
this.size_ = null;
this.currentCellControl_.dispose();
};
/**
* Overrides {@link goog.ui.Control#setContentInternal} by also updating the
* grid size and the selection model. Considered protected.
* @param {goog.ui.ControlContent} content Array of DOM nodes to be displayed
* as items in the palette grid (one item per cell).
* @protected
* @override
*/
goog.ui.Palette.prototype.setContentInternal = function(content) {
'use strict';
var items = /** @type {Array<Node>} */ (content);
goog.ui.Palette.superClass_.setContentInternal.call(this, items);
// Adjust the palette size.
this.adjustSize_();
// Add the items to the selection model, replacing previous items (if any).
if (this.selectionModel_) {
// We already have a selection model; just replace the items.
this.selectionModel_.clear();
this.selectionModel_.addItems(items);
} else {
// Create a selection model, initialize the items, and hook up handlers.
this.selectionModel_ = new goog.ui.SelectionModel(items);
this.selectionModel_.setSelectionHandler(goog.bind(this.selectItem_, this));
this.getHandler().listen(
this.selectionModel_, goog.events.EventType.SELECT,
this.handleSelectionChange);
}
// In all cases, clear the highlight.
this.highlightedIndex_ = -1;
};
/**
* Overrides {@link goog.ui.Control#getCaption} to return the empty string,
* since palettes don't have text captions.
* @return {string} The empty string.
* @override
*/
goog.ui.Palette.prototype.getCaption = function() {
'use strict';
return '';
};
/**
* Overrides {@link goog.ui.Control#setCaption} to be a no-op, since palettes
* don't have text captions.
* @param {string} caption Ignored.
* @override
*/
goog.ui.Palette.prototype.setCaption = function(caption) {
// Do nothing.
};
// Palette event handling.
/**
* Handles mouseover events. Overrides {@link goog.ui.Control#handleMouseOver}
* by determining which palette item (if any) was moused over, highlighting it,
* and un-highlighting any previously-highlighted item.
* @param {goog.events.BrowserEvent} e Mouse event to handle.
* @override
*/
goog.ui.Palette.prototype.handleMouseOver = function(e) {
'use strict';
goog.ui.Palette.superClass_.handleMouseOver.call(this, e);
var item = this.getRenderer().getContainingItem(this, e.target);
if (item && e.relatedTarget && goog.dom.contains(item, e.relatedTarget)) {
// Ignore internal mouse moves.
return;
}
if (item != this.getHighlightedItem()) {
this.setHighlightedItem(item);
}
};
/**
* Handles mousedown events. Overrides {@link goog.ui.Control#handleMouseDown}
* by ensuring that the item on which the user moused down is highlighted.
* @param {goog.events.Event} e Mouse event to handle.
* @override
*/
goog.ui.Palette.prototype.handleMouseDown = function(e) {
'use strict';
goog.ui.Palette.superClass_.handleMouseDown.call(this, e);
if (this.isActive()) {
// Make sure we move the highlight to the cell on which the user moused
// down.
var item = this.getRenderer().getContainingItem(this, e.target);
if (item != this.getHighlightedItem()) {
this.setHighlightedItem(item);
}
}
};
/**
* Selects the currently highlighted palette item (triggered by mouseup or by
* keyboard action). Overrides {@link goog.ui.Control#performActionInternal}
* by selecting the highlighted item and dispatching an ACTION event.
* @param {goog.events.Event} e Mouse or key event that triggered the action.
* @return {boolean} True if the action was allowed to proceed, false otherwise.
* @override
*/
goog.ui.Palette.prototype.performActionInternal = function(e) {
'use strict';
var highlightedItem = this.getHighlightedItem();
if (highlightedItem) {
if (e && this.shouldSelectHighlightedItem_(e)) {
this.setSelectedItem(highlightedItem);
}
return goog.ui.Palette.base(this, 'performActionInternal', e);
}
return false;
};
/**
* Determines whether to select the highlighted item while handling an internal
* action. The highlighted item should not be selected if the action is a mouse
* event occurring outside the palette or in an "empty" cell.
* @param {!goog.events.Event} e Mouseup or key event being handled.
* @return {boolean} True if the highlighted item should be selected.
* @private
*/
goog.ui.Palette.prototype.shouldSelectHighlightedItem_ = function(e) {
'use strict';
if (!this.getSelectedItem()) {
// It's always ok to select when nothing is selected yet.
return true;
} else if (e.type != 'mouseup') {
// Keyboard can only act on valid cells.
return true;
} else {
// Return whether or not the mouse action was in the palette.
return !!this.getRenderer().getContainingItem(this, e.target);
}
};
/**
* Handles keyboard events dispatched while the palette has focus. Moves the
* highlight on arrow keys, and selects the highlighted item on Enter or Space.
* Returns true if the event was handled, false otherwise. In particular, if
* the user attempts to navigate out of the grid, the highlight isn't changed,
* and this method returns false; it is then up to the parent component to
* handle the event (e.g. by wrapping the highlight around). Overrides {@link
* goog.ui.Control#handleKeyEvent}.
* @param {goog.events.KeyEvent} e Key event to handle.
* @return {boolean} True iff the key event was handled by the component.
* @override
*/
goog.ui.Palette.prototype.handleKeyEvent = function(e) {
'use strict';
var items = this.getContent();
var numItems = items ? items.length : 0;
var numColumns = this.size_.width;
// If the component is disabled or the palette is empty, bail.
if (numItems == 0 || !this.isEnabled()) {
return false;
}
// User hit ENTER or SPACE; trigger action.
if (e.keyCode == goog.events.KeyCodes.ENTER ||
e.keyCode == goog.events.KeyCodes.SPACE) {
return this.performActionInternal(e);
}
// User hit HOME or END; move highlight.
if (e.keyCode == goog.events.KeyCodes.HOME) {
this.setHighlightedIndexInternal_(0, true /* scrollIntoView */);
return true;
} else if (e.keyCode == goog.events.KeyCodes.END) {
this.setHighlightedIndexInternal_(numItems - 1, true /* scrollIntoView */);
return true;
}
// If nothing is highlighted, start from the selected index. If nothing is
// selected either, highlightedIndex is -1.
var highlightedIndex = this.highlightedIndex_ < 0 ? this.getSelectedIndex() :
this.highlightedIndex_;
switch (e.keyCode) {
case goog.events.KeyCodes.LEFT:
// If the highlighted index is uninitialized, or is at the beginning, move
// it to the end.
if (highlightedIndex == -1 || highlightedIndex == 0) {
highlightedIndex = numItems;
}
this.setHighlightedIndexInternal_(
highlightedIndex - 1, true /* scrollIntoView */);
e.preventDefault();
return true;
break;
case goog.events.KeyCodes.RIGHT:
// If the highlighted index at the end, move it to the beginning.
if (highlightedIndex == numItems - 1) {
highlightedIndex = -1;
}
this.setHighlightedIndexInternal_(
highlightedIndex + 1, true /* scrollIntoView */);
e.preventDefault();
return true;
break;
case goog.events.KeyCodes.UP:
if (highlightedIndex == -1) {
highlightedIndex = numItems + numColumns - 1;
}
if (highlightedIndex >= numColumns) {
this.setHighlightedIndexInternal_(
highlightedIndex - numColumns, true /* scrollIntoView */);
e.preventDefault();
return true;
}
break;
case goog.events.KeyCodes.DOWN:
if (highlightedIndex == -1) {
highlightedIndex = -numColumns;
}
if (highlightedIndex < numItems - numColumns) {
this.setHighlightedIndexInternal_(
highlightedIndex + numColumns, true /* scrollIntoView */);
e.preventDefault();
return true;
}
break;
}
return false;
};
/**
* Handles selection change events dispatched by the selection model.
* @param {goog.events.Event} e Selection event to handle.
*/
goog.ui.Palette.prototype.handleSelectionChange = function(e) {
// No-op in the base class.
};
// Palette management.
/**
* Returns the size of the palette grid.
* @return {goog.math.Size} Palette size (columns x rows).
*/
goog.ui.Palette.prototype.getSize = function() {
'use strict';
return this.size_;
};
/**
* Sets the size of the palette grid to the given size. Callers can either
* pass a single {@link goog.math.Size} or a pair of numbers (first the number
* of columns, then the number of rows) to this method. In both cases, the
* number of rows is optional and will be calculated automatically if needed.
* It is an error to attempt to change the size of the palette after it has
* been rendered.
* @param {goog.math.Size|number} size Either a size object or the number of
* columns.
* @param {number=} opt_rows The number of rows (optional).
*/
goog.ui.Palette.prototype.setSize = function(size, opt_rows) {
'use strict';
if (this.getElement()) {
throw new Error(goog.ui.Component.Error.ALREADY_RENDERED);
}
this.size_ = (typeof size === 'number') ?
new goog.math.Size(size, /** @type {number} */ (opt_rows)) :
size;
// Adjust size, if needed.
this.adjustSize_();
};
/**
* Returns the 0-based index of the currently highlighted palette item, or -1
* if no item is highlighted.
* @return {number} Index of the highlighted item (-1 if none).
*/
goog.ui.Palette.prototype.getHighlightedIndex = function() {
'use strict';
return this.highlightedIndex_;
};
/**
* Returns the currently highlighted palette item, or null if no item is
* highlighted.
* @return {Node} The highlighted item (undefined if none).
*/
goog.ui.Palette.prototype.getHighlightedItem = function() {
'use strict';
var items = this.getContent();
return items && items[this.highlightedIndex_];
};
/**
* @return {Element} The highlighted cell.
* @private
*/
goog.ui.Palette.prototype.getHighlightedCellElement_ = function() {
'use strict';
return this.getRenderer().getCellForItem(this.getHighlightedItem());
};
/**
* Highlights the item at the given 0-based index, or removes the highlight
* if the argument is -1 or out of range. Any previously-highlighted item
* will be un-highlighted.
* @param {number} index 0-based index of the item to highlight.
*/
goog.ui.Palette.prototype.setHighlightedIndex = function(index) {
'use strict';
this.setHighlightedIndexInternal_(index, false /* scrollIntoView */);
};
/**
* @param {number} index 0-based index of the item to highlight.
* @param {boolean} scrollIntoView Whether to bring the highlighted item into
* view by potentially scrolling the palette's container. This has no effect
* if the palette is not in a scrollbale container.
* @private
*/
goog.ui.Palette.prototype.setHighlightedIndexInternal_ = function(
index, scrollIntoView) {
'use strict';
if (index != this.highlightedIndex_) {
this.highlightIndex_(this.highlightedIndex_, false);
this.lastHighlightedIndex_ = this.highlightedIndex_;
this.highlightedIndex_ = index;
this.highlightIndex_(index, true);
if (scrollIntoView) {
var highlightedElement = goog.asserts.assert(
this.getHighlightedCellElement_(),
'Highlighted item must exist to scroll to make it visible in ' +
'container. Please check that index is non-negative and valid.');
goog.style.scrollIntoContainerView(
highlightedElement, this.getParent().getElementStrict());
}
this.dispatchEvent(goog.ui.Palette.EventType.AFTER_HIGHLIGHT);
}
};
/**
* Highlights the given item, or removes the highlight if the argument is null
* or invalid. Any previously-highlighted item will be un-highlighted.
* @param {Node|undefined} item Item to highlight.
*/
goog.ui.Palette.prototype.setHighlightedItem = function(item) {
'use strict';
var items = /** @type {Array<Node>} */ (this.getContent());
this.setHighlightedIndex((items && item) ? items.indexOf(item) : -1);
};
/**
* Returns the 0-based index of the currently selected palette item, or -1
* if no item is selected.
* @return {number} Index of the selected item (-1 if none).
*/
goog.ui.Palette.prototype.getSelectedIndex = function() {
'use strict';
return this.selectionModel_ ? this.selectionModel_.getSelectedIndex() : -1;
};
/**
* Returns the currently selected palette item, or null if no item is selected.
* @return {Node} The selected item (null if none).
*/
goog.ui.Palette.prototype.getSelectedItem = function() {
'use strict';
return this.selectionModel_ ?
/** @type {Node} */ (this.selectionModel_.getSelectedItem()) :
null;
};
/**
* Selects the item at the given 0-based index, or clears the selection
* if the argument is -1 or out of range. Any previously-selected item
* will be deselected.
* @param {number} index 0-based index of the item to select.
*/
goog.ui.Palette.prototype.setSelectedIndex = function(index) {
'use strict';
if (this.selectionModel_) {
this.selectionModel_.setSelectedIndex(index);
}
};
/**
* Selects the given item, or clears the selection if the argument is null or
* invalid. Any previously-selected item will be deselected.
* @param {Node} item Item to select.
*/
goog.ui.Palette.prototype.setSelectedItem = function(item) {
'use strict';
if (this.selectionModel_) {
this.selectionModel_.setSelectedItem(item);
}
};
/**
* Private helper; highlights or un-highlights the item at the given index
* based on the value of the Boolean argument. This implementation simply
* applies highlight styling to the cell containing the item to be highighted.
* Does nothing if the palette hasn't been rendered yet.
* @param {number} index 0-based index of item to highlight or un-highlight.
* @param {boolean} highlight If true, the item is highlighted; otherwise it
* is un-highlighted.
* @private
*/
goog.ui.Palette.prototype.highlightIndex_ = function(index, highlight) {
'use strict';
if (this.getElement()) {
var items = this.getContent();
if (items && index >= 0 && index < items.length) {
var cellEl = this.getHighlightedCellElement_();
if (this.currentCellControl_.getElement() != cellEl) {
this.currentCellControl_.setElementInternal(cellEl);
}
if (this.currentCellControl_.tryHighlight(highlight)) {
this.getRenderer().highlightCell(this, items[index], highlight);
}
}
}
};
/** @override */
goog.ui.Palette.prototype.setHighlighted = function(highlight) {
'use strict';
if (highlight && this.highlightedIndex_ == -1) {
// If there was a last highlighted index, use that. Otherwise, highlight the
// first cell.
this.setHighlightedIndex(
this.lastHighlightedIndex_ > -1 ? this.lastHighlightedIndex_ : 0);
} else if (!highlight) {
this.setHighlightedIndex(-1);
}
// The highlight event should be fired once the component has updated its own
// state.
goog.ui.Palette.base(this, 'setHighlighted', highlight);
};
/**
* Private helper; selects or deselects the given item based on the value of
* the Boolean argument. This implementation simply applies selection styling
* to the cell containing the item to be selected. Does nothing if the palette
* hasn't been rendered yet.
* @param {Node} item Item to select or deselect.
* @param {boolean} select If true, the item is selected; otherwise it is
* deselected.
* @private
*/
goog.ui.Palette.prototype.selectItem_ = function(item, select) {
'use strict';
if (this.getElement()) {
this.getRenderer().selectCell(this, item, select);
}
};
/**
* Calculates and updates the size of the palette based on any preset values
* and the number of palette items. If there is no preset size, sets the
* palette size to the smallest square big enough to contain all items. If
* there is a preset number of columns, increases the number of rows to hold
* all items if needed. (If there are too many rows, does nothing.)
* @private
*/
goog.ui.Palette.prototype.adjustSize_ = function() {
'use strict';
var items = this.getContent();
if (items) {
if (this.size_ && this.size_.width) {
// There is already a size set; honor the number of columns (if >0), but
// increase the number of rows if needed.
var minRows = Math.ceil(items.length / this.size_.width);
if (typeof this.size_.height !== 'number' ||
this.size_.height < minRows) {
this.size_.height = minRows;
}
} else {
// No size has been set; size the grid to the smallest square big enough
// to hold all items (hey, why not?).
var length = Math.ceil(Math.sqrt(items.length));
this.size_ = new goog.math.Size(length, length);
}
} else {
// No items; set size to 0x0.
this.size_ = new goog.math.Size(0, 0);
}
};
/**
* A component to represent the currently highlighted cell.
* @constructor
* @extends {goog.ui.Control}
* @private
*/
goog.ui.Palette.CurrentCell_ = function() {
'use strict';
goog.ui.Palette.CurrentCell_.base(this, 'constructor', null);
this.setDispatchTransitionEvents(goog.ui.Component.State.HOVER, true);
};
goog.inherits(goog.ui.Palette.CurrentCell_, goog.ui.Control);
/**
* @param {boolean} highlight Whether to highlight or unhighlight the component.
* @return {boolean} Whether it was successful.
*/
goog.ui.Palette.CurrentCell_.prototype.tryHighlight = function(highlight) {
'use strict';
this.setHighlighted(highlight);
return this.isHighlighted() == highlight;
};
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