gnome-shell/js/ui/slider.js

210 lines
6.8 KiB
JavaScript

/* -*- mode: js2; js2-basic-offset: 4; indent-tabs-mode: nil -*- */
const { Atk, Clutter } = imports.gi;
const Signals = imports.signals;
const BarLevel = imports.ui.barLevel;
var SLIDER_SCROLL_STEP = 0.02; /* Slider scrolling step in % */
var Slider = class extends BarLevel.BarLevel {
constructor(value) {
let params = {
styleClass: 'slider',
canFocus: true,
reactive: true,
accessibleRole: Atk.Role.SLIDER,
};
super(value, params);
this.actor.connect('button-press-event', this._startDragging.bind(this));
this.actor.connect('touch-event', this._touchDragging.bind(this));
this.actor.connect('scroll-event', this._onScrollEvent.bind(this));
this.actor.connect('key-press-event', this.onKeyPressEvent.bind(this));
this._releaseId = this._motionId = 0;
this._dragging = false;
this._customAccessible.connect('get-minimum-increment', this._getMinimumIncrement.bind(this));
}
_barLevelRepaint(area) {
super._barLevelRepaint(area);
// Add handle
let cr = area.get_context();
let themeNode = area.get_theme_node();
let [width, height] = area.get_surface_size();
let handleRadius = themeNode.get_length('-slider-handle-radius');
let handleBorderWidth = themeNode.get_length('-slider-handle-border-width');
let [hasHandleColor, handleBorderColor] =
themeNode.lookup_color('-slider-handle-border-color', false);
let handleX = handleRadius + (width - 2 * handleRadius) * this._value / this._maxValue;
let handleY = height / 2;
let color = themeNode.get_foreground_color();
Clutter.cairo_set_source_color(cr, color);
cr.arc(handleX, handleY, handleRadius, 0, 2 * Math.PI);
cr.fillPreserve();
if (hasHandleColor && handleBorderWidth) {
Clutter.cairo_set_source_color(cr, handleBorderColor);
cr.setLineWidth(handleBorderWidth);
cr.stroke();
}
cr.$dispose();
}
_startDragging(actor, event) {
return this.startDragging(event);
}
startDragging(event) {
if (this._dragging)
return Clutter.EVENT_PROPAGATE;
this._dragging = true;
let device = event.get_device();
let sequence = event.get_event_sequence();
if (sequence != null)
device.sequence_grab(sequence, this.actor);
else
device.grab(this.actor);
this._grabbedDevice = device;
this._grabbedSequence = sequence;
if (sequence == null) {
this._releaseId = this.actor.connect('button-release-event', this._endDragging.bind(this));
this._motionId = this.actor.connect('motion-event', this._motionEvent.bind(this));
}
// We need to emit 'drag-begin' before moving the handle to make
// sure that no 'value-changed' signal is emitted before this one.
this.emit('drag-begin');
let absX, absY;
[absX, absY] = event.get_coords();
this._moveHandle(absX, absY);
return Clutter.EVENT_STOP;
}
_endDragging() {
if (this._dragging) {
if (this._releaseId)
this.actor.disconnect(this._releaseId);
if (this._motionId)
this.actor.disconnect(this._motionId);
if (this._grabbedSequence != null)
this._grabbedDevice.sequence_ungrab(this._grabbedSequence);
else
this._grabbedDevice.ungrab();
this._grabbedSequence = null;
this._grabbedDevice = null;
this._dragging = false;
this.emit('drag-end');
}
return Clutter.EVENT_STOP;
}
_touchDragging(actor, event) {
let device = event.get_device();
let sequence = event.get_event_sequence();
if (!this._dragging &&
event.type() == Clutter.EventType.TOUCH_BEGIN) {
this.startDragging(event);
return Clutter.EVENT_STOP;
} else if (device.sequence_get_grabbed_actor(sequence) == actor) {
if (event.type() == Clutter.EventType.TOUCH_UPDATE)
return this._motionEvent(actor, event);
else if (event.type() == Clutter.EventType.TOUCH_END)
return this._endDragging();
}
return Clutter.EVENT_PROPAGATE;
}
scroll(event) {
let direction = event.get_scroll_direction();
let delta;
if (event.is_pointer_emulated())
return Clutter.EVENT_PROPAGATE;
if (direction == Clutter.ScrollDirection.DOWN) {
delta = -SLIDER_SCROLL_STEP;
} else if (direction == Clutter.ScrollDirection.UP) {
delta = SLIDER_SCROLL_STEP;
} else if (direction == Clutter.ScrollDirection.SMOOTH) {
let [dx, dy] = event.get_scroll_delta();
// Even though the slider is horizontal, use dy to match
// the UP/DOWN above.
delta = -dy * SLIDER_SCROLL_STEP;
}
this._value = Math.min(Math.max(0, this._value + delta), this._maxValue);
this.actor.queue_repaint();
this.emit('value-changed', this._value);
return Clutter.EVENT_STOP;
}
_onScrollEvent(actor, event) {
return this.scroll(event);
}
_motionEvent(actor, event) {
let absX, absY;
[absX, absY] = event.get_coords();
this._moveHandle(absX, absY);
return Clutter.EVENT_STOP;
}
onKeyPressEvent(actor, event) {
let key = event.get_key_symbol();
if (key == Clutter.KEY_Right || key == Clutter.KEY_Left) {
let delta = key == Clutter.KEY_Right ? 0.1 : -0.1;
this._value = Math.max(0, Math.min(this._value + delta, this._maxValue));
this.actor.queue_repaint();
this.emit('drag-begin');
this.emit('value-changed', this._value);
this.emit('drag-end');
return Clutter.EVENT_STOP;
}
return Clutter.EVENT_PROPAGATE;
}
_moveHandle(absX, absY) {
let relX, sliderX;
[sliderX] = this.actor.get_transformed_position();
relX = absX - sliderX;
let width = this._barLevelWidth;
let handleRadius = this.actor.get_theme_node().get_length('-slider-handle-radius');
let newvalue;
if (relX < handleRadius)
newvalue = 0;
else if (relX > width - handleRadius)
newvalue = 1;
else
newvalue = (relX - handleRadius) / (width - 2 * handleRadius);
this._value = newvalue * this._maxValue;
this.actor.queue_repaint();
this.emit('value-changed', this._value);
}
_getMinimumIncrement(actor) {
return 0.1;
}
};
Signals.addSignalMethods(Slider.prototype);