1 files changed, 293 insertions, 0 deletions
diff --git a/js/ui/lightbox.js b/js/ui/lightbox.js
new file mode 100644
index 0000000..9aaef1a
--- /dev/null
+++ b/js/ui/lightbox.js
@@ -0,0 +1,293 @@
+// -*- mode: js; js-indent-level: 4; indent-tabs-mode: nil -*-
+/* exported Lightbox */
+
+const { Clutter, GObject, Shell, St } = imports.gi;
+
+const Params = imports.misc.params;
+
+var DEFAULT_FADE_FACTOR = 0.4;
+var VIGNETTE_BRIGHTNESS = 0.5;
+var VIGNETTE_SHARPNESS = 0.7;
+
+const VIGNETTE_DECLARATIONS = '\
+uniform float brightness;\n\
+uniform float vignette_sharpness;\n';
+
+const VIGNETTE_CODE = '\
+cogl_color_out.a = cogl_color_in.a;\n\
+cogl_color_out.rgb = vec3(0.0, 0.0, 0.0);\n\
+vec2 position = cogl_tex_coord_in[0].xy - 0.5;\n\
+float t = length(2.0 * position);\n\
+t = clamp(t, 0.0, 1.0);\n\
+float pixel_brightness = mix(1.0, 1.0 - vignette_sharpness, t);\n\
+cogl_color_out.a = cogl_color_out.a * (1 - pixel_brightness * brightness);';
+
+var RadialShaderEffect = GObject.registerClass({
+    Properties: {
+        'brightness': GObject.ParamSpec.float(
+            'brightness', 'brightness', 'brightness',
+            GObject.ParamFlags.READWRITE,
+            0, 1, 1),
+        'sharpness': GObject.ParamSpec.float(
+            'sharpness', 'sharpness', 'sharpness',
+            GObject.ParamFlags.READWRITE,
+            0, 1, 0),
+    },
+}, class RadialShaderEffect extends Shell.GLSLEffect {
+    _init(params) {
+        this._brightness = undefined;
+        this._sharpness = undefined;
+
+        super._init(params);
+
+        this._brightnessLocation = this.get_uniform_location('brightness');
+        this._sharpnessLocation = this.get_uniform_location('vignette_sharpness');
+
+        this.brightness = 1.0;
+        this.sharpness = 0.0;
+    }
+
+    vfunc_build_pipeline() {
+        this.add_glsl_snippet(Shell.SnippetHook.FRAGMENT,
+                              VIGNETTE_DECLARATIONS, VIGNETTE_CODE, true);
+    }
+
+    get brightness() {
+        return this._brightness;
+    }
+
+    set brightness(v) {
+        if (this._brightness == v)
+            return;
+        this._brightness = v;
+        this.set_uniform_float(this._brightnessLocation,
+                               1, [this._brightness]);
+        this.notify('brightness');
+    }
+
+    get sharpness() {
+        return this._sharpness;
+    }
+
+    set sharpness(v) {
+        if (this._sharpness == v)
+            return;
+        this._sharpness = v;
+        this.set_uniform_float(this._sharpnessLocation,
+                               1, [this._sharpness]);
+        this.notify('sharpness');
+    }
+});
+
+/**
+ * Lightbox:
+ * @container: parent Clutter.Container
+ * @params: (optional) additional parameters:
+ *           - inhibitEvents: whether to inhibit events for @container
+ *           - width: shade actor width
+ *           - height: shade actor height
+ *           - fadeFactor: fading opacity factor
+ *           - radialEffect: whether to enable the GLSL radial effect
+ *
+ * Lightbox creates a dark translucent "shade" actor to hide the
+ * contents of @container, and allows you to specify particular actors
+ * in @container to highlight by bringing them above the shade. It
+ * tracks added and removed actors in @container while the lightboxing
+ * is active, and ensures that all actors are returned to their
+ * original stacking order when the lightboxing is removed. (However,
+ * if actors are restacked by outside code while the lightboxing is
+ * active, the lightbox may later revert them back to their original
+ * order.)
+ *
+ * By default, the shade window will have the height and width of
+ * @container and will track any changes in its size. You can override
+ * this by passing an explicit width and height in @params.
+ */
+var Lightbox = GObject.registerClass({
+    Properties: {
+        'active': GObject.ParamSpec.boolean(
+            'active', 'active', 'active', GObject.ParamFlags.READABLE, false),
+    },
+}, class Lightbox extends St.Bin {
+    _init(container, params) {
+        params = Params.parse(params, {
+            inhibitEvents: false,
+            width: null,
+            height: null,
+            fadeFactor: DEFAULT_FADE_FACTOR,
+            radialEffect: false,
+        });
+
+        super._init({
+            reactive: params.inhibitEvents,
+            width: params.width,
+            height: params.height,
+            visible: false,
+        });
+
+        this._active = false;
+        this._container = container;
+        this._children = container.get_children();
+        this._fadeFactor = params.fadeFactor;
+        this._radialEffect = Clutter.feature_available(Clutter.FeatureFlags.SHADERS_GLSL) && params.radialEffect;
+
+        if (this._radialEffect)
+            this.add_effect(new RadialShaderEffect({ name: 'radial' }));
+        else
+            this.set({ opacity: 0, style_class: 'lightbox' });
+
+        container.add_actor(this);
+        container.set_child_above_sibling(this, null);
+
+        this.connect('destroy', this._onDestroy.bind(this));
+
+        if (!params.width || !params.height) {
+            this.add_constraint(new Clutter.BindConstraint({
+                source: container,
+                coordinate: Clutter.BindCoordinate.ALL,
+            }));
+        }
+
+        this._actorAddedSignalId = container.connect('actor-added', this._actorAdded.bind(this));
+        this._actorRemovedSignalId = container.connect('actor-removed', this._actorRemoved.bind(this));
+
+        this._highlighted = null;
+    }
+
+    get active() {
+        return this._active;
+    }
+
+    _actorAdded(container, newChild) {
+        let children = this._container.get_children();
+        let myIndex = children.indexOf(this);
+        let newChildIndex = children.indexOf(newChild);
+
+        if (newChildIndex > myIndex) {
+            // The child was added above the shade (presumably it was
+            // made the new top-most child). Move it below the shade,
+            // and add it to this._children as the new topmost actor.
+            this._container.set_child_above_sibling(this, newChild);
+            this._children.push(newChild);
+        } else if (newChildIndex == 0) {
+            // Bottom of stack
+            this._children.unshift(newChild);
+        } else {
+            // Somewhere else; insert it into the correct spot
+            let prevChild = this._children.indexOf(children[newChildIndex - 1]);
+            if (prevChild != -1) // paranoia
+                this._children.splice(prevChild + 1, 0, newChild);
+        }
+    }
+
+    lightOn(fadeInTime) {
+        this.remove_all_transitions();
+
+        let easeProps = {
+            duration: fadeInTime || 0,
+            mode: Clutter.AnimationMode.EASE_OUT_QUAD,
+        };
+
+        let onComplete = () => {
+            this._active = true;
+            this.notify('active');
+        };
+
+        this.show();
+
+        if (this._radialEffect) {
+            this.ease_property(
+                '@effects.radial.brightness', VIGNETTE_BRIGHTNESS, easeProps);
+            this.ease_property(
+                '@effects.radial.sharpness', VIGNETTE_SHARPNESS,
+                Object.assign({ onComplete }, easeProps));
+        } else {
+            this.ease(Object.assign(easeProps, {
+                opacity: 255 * this._fadeFactor,
+                onComplete,
+            }));
+        }
+    }
+
+    lightOff(fadeOutTime) {
+        this.remove_all_transitions();
+
+        this._active = false;
+        this.notify('active');
+
+        let easeProps = {
+            duration: fadeOutTime || 0,
+            mode: Clutter.AnimationMode.EASE_OUT_QUAD,
+        };
+
+        let onComplete = () => this.hide();
+
+        if (this._radialEffect) {
+            this.ease_property(
+                '@effects.radial.brightness', 1.0, easeProps);
+            this.ease_property(
+                '@effects.radial.sharpness', 0.0, Object.assign({ onComplete }, easeProps));
+        } else {
+            this.ease(Object.assign(easeProps, { opacity: 0, onComplete }));
+        }
+    }
+
+    _actorRemoved(container, child) {
+        let index = this._children.indexOf(child);
+        if (index != -1) // paranoia
+            this._children.splice(index, 1);
+
+        if (child == this._highlighted)
+            this._highlighted = null;
+    }
+
+    /**
+     * highlight:
+     * @param {Clutter.Actor=} window: actor to highlight
+     *
+     * Highlights the indicated actor and unhighlights any other
+     * currently-highlighted actor. With no arguments or a false/null
+     * argument, all actors will be unhighlighted.
+     */
+    highlight(window) {
+        if (this._highlighted == window)
+            return;
+
+        // Walk this._children raising and lowering actors as needed.
+        // Things get a little tricky if the to-be-raised and
+        // to-be-lowered actors were originally adjacent, in which
+        // case we may need to indicate some *other* actor as the new
+        // sibling of the to-be-lowered one.
+
+        let below = this;
+        for (let i = this._children.length - 1; i >= 0; i--) {
+            if (this._children[i] == window)
+                this._container.set_child_above_sibling(this._children[i], null);
+            else if (this._children[i] == this._highlighted)
+                this._container.set_child_below_sibling(this._children[i], below);
+            else
+                below = this._children[i];
+        }
+
+        this._highlighted = window;
+    }
+
+    /**
+     * _onDestroy:
+     *
+     * This is called when the lightbox' actor is destroyed, either
+     * by destroying its container or by explicitly calling this.destroy().
+     */
+    _onDestroy() {
+        if (this._actorAddedSignalId) {
+            this._container.disconnect(this._actorAddedSignalId);
+            this._actorAddedSignalId = 0;
+        }
+        if (this._actorRemovedSignalId) {
+            this._container.disconnect(this._actorRemovedSignalId);
+            this._actorRemovedSignalId = 0;
+        }
+
+        this.highlight(null);
+    }
+});