Userland: Add new app called Assistant

'Assistant' is similar to macOS spotlight where you can quickly open a
text input, start typing, and hit 'enter' to launch apps or open
directories.

Userland/Applications/Assistant/Providers.h

@@ -0,0 +1,95 @@
+/*
+ * Copyright (c) 2021, Spencer Dixon <spencercdixon@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/String.h>
+#include <LibDesktop/AppFile.h>
+#include <LibGUI/Desktop.h>
+#include <LibJS/Interpreter.h>
+#include <LibJS/Runtime/VM.h>
+
+namespace Assistant {
+
+class Result : public RefCounted<Result> {
+public:
+    enum class Kind {
+        Unknown,
+        App,
+        Calculator,
+    };
+
+    virtual ~Result() = default;
+
+    virtual void activate() const = 0;
+
+    RefPtr<Gfx::Bitmap> bitmap() { return m_bitmap; }
+    String const& title() const { return m_title; }
+    Kind kind() const { return m_kind; }
+    int score() const { return m_score; }
+    bool equals(Result const& other) const
+    {
+        return title() == other.title() && kind() == other.kind();
+    }
+
+protected:
+    Result(RefPtr<Gfx::Bitmap> bitmap, String title, int score = 0, Kind kind = Kind::Unknown)
+        : m_bitmap(move(bitmap))
+        , m_title(move(title))
+        , m_score(score)
+        , m_kind(kind)
+    {
+    }
+
+private:
+    RefPtr<Gfx::Bitmap> m_bitmap;
+    String m_title;
+    int m_score { 0 };
+    Kind m_kind;
+};
+
+class AppResult : public Result {
+public:
+    AppResult(RefPtr<Gfx::Bitmap> bitmap, String title, NonnullRefPtr<Desktop::AppFile> af, int score)
+        : Result(move(bitmap), move(title), score, Kind::App)
+        , m_app_file(move(af))
+    {
+    }
+    ~AppResult() override = default;
+    void activate() const override;
+
+private:
+    NonnullRefPtr<Desktop::AppFile> m_app_file;
+};
+
+class CalculatorResult : public Result {
+public:
+    explicit CalculatorResult(String title)
+        : Result(GUI::Icon::default_icon("app-calculator").bitmap_for_size(16), move(title), 100, Kind::Calculator)
+    {
+    }
+    ~CalculatorResult() override = default;
+    void activate() const override;
+};
+
+class Provider {
+public:
+    virtual ~Provider() = default;
+
+    virtual void query(const String&, Function<void(Vector<NonnullRefPtr<Result>>)> on_complete) = 0;
+};
+
+class AppProvider : public Provider {
+public:
+    void query(String const& query, Function<void(Vector<NonnullRefPtr<Result>>)> on_complete) override;
+};
+
+class CalculatorProvider : public Provider {
+public:
+    void query(String const& query, Function<void(Vector<NonnullRefPtr<Result>>)> on_complete) override;
+};
+
+}