gnome-shell/js/ui/pageIndicators.js

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// -*- mode: js; js-indent-level: 4; indent-tabs-mode: nil -*-
/* exported PageIndicators */
const { Clutter, Graphene, GObject, St } = imports.gi;
const INDICATOR_INACTIVE_OPACITY = 128;
const INDICATOR_INACTIVE_OPACITY_HOVER = 255;
const INDICATOR_INACTIVE_SCALE = 2 / 3;
const INDICATOR_INACTIVE_SCALE_PRESSED = 0.5;
var PageIndicators = GObject.registerClass({
Signals: { 'page-activated': { param_types: [GObject.TYPE_INT] } },
}, class PageIndicators extends St.BoxLayout {
_init(orientation = Clutter.Orientation.VERTICAL) {
let vertical = orientation == Clutter.Orientation.VERTICAL;
super._init({
style_class: 'page-indicators',
vertical,
x_expand: true, y_expand: true,
x_align: vertical ? Clutter.ActorAlign.END : Clutter.ActorAlign.CENTER,
y_align: vertical ? Clutter.ActorAlign.CENTER : Clutter.ActorAlign.END,
reactive: true,
clip_to_allocation: true,
});
this._nPages = 0;
this._currentPosition = 0;
this._reactive = true;
this._reactive = true;
this._orientation = orientation;
}
vfunc_get_preferred_height(forWidth) {
// We want to request the natural height of all our children as our
// natural height, so we chain up to St.BoxLayout, but we only request 0
// as minimum height, since it's not that important if some indicators
// are not shown
let [, natHeight] = super.vfunc_get_preferred_height(forWidth);
return [0, natHeight];
}
setReactive(reactive) {
let children = this.get_children();
for (let i = 0; i < children.length; i++)
children[i].reactive = reactive;
this._reactive = reactive;
}
setNPages(nPages) {
if (this._nPages == nPages)
return;
let diff = nPages - this._nPages;
if (diff > 0) {
for (let i = 0; i < diff; i++) {
let pageIndex = this._nPages + i;
let indicator = new St.Button({ style_class: 'page-indicator',
button_mask: St.ButtonMask.ONE |
St.ButtonMask.TWO |
St.ButtonMask.THREE,
reactive: this._reactive });
indicator.child = new St.Widget({
style_class: 'page-indicator-icon',
pivot_point: new Graphene.Point({ x: 0.5, y: 0.5 }),
});
indicator.connect('clicked', () => {
this.emit('page-activated', pageIndex);
});
indicator.connect('notify::hover', () => {
this._updateIndicator(indicator, pageIndex);
});
indicator.connect('notify::pressed', () => {
this._updateIndicator(indicator, pageIndex);
});
this._updateIndicator(indicator, pageIndex);
this.add_actor(indicator);
}
} else {
let children = this.get_children().splice(diff);
for (let i = 0; i < children.length; i++)
children[i].destroy();
}
this._nPages = nPages;
this.visible = this._nPages > 1;
}
_updateIndicator(indicator, pageIndex) {
let progress =
Math.max(1 - Math.abs(this._currentPosition - pageIndex), 0);
let inactiveScale = indicator.pressed
? INDICATOR_INACTIVE_SCALE_PRESSED : INDICATOR_INACTIVE_SCALE;
let inactiveOpacity = indicator.hover
? INDICATOR_INACTIVE_OPACITY_HOVER : INDICATOR_INACTIVE_OPACITY;
let scale = inactiveScale + (1 - inactiveScale) * progress;
let opacity = inactiveOpacity + (255 - inactiveOpacity) * progress;
indicator.child.set_scale(scale, scale);
indicator.child.opacity = opacity;
}
setCurrentPosition(currentPosition) {
this._currentPosition = currentPosition;
let children = this.get_children();
for (let i = 0; i < children.length; i++)
this._updateIndicator(children[i], i);
}
get nPages() {
return this._nPages;
}
});