Initial commit of ferret: command-line search

There are still some issues with launching a sub-program from within Cursive
that have not been solved (see: https://github.com/gyscos/Cursive/issues/199).
But, it works for the most part.

.gitignore

@@ -0,0 +1,3 @@
+
+/target/
+**/*.rs.bk

Cargo.toml

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+[package]
+name = "ferret"
+version = "0.1.0"
+authors = ["Tyler Hallada <tyler@hallada.net>"]
+
+[dependencies]
+termion = "1.5.1"
+tui = "0.2.0"
+liner = "0.4.4"
+reqwest = "0.8.4"
+scraper = "0.4.0"
+chan = "0.1.20"
+
+[dependencies.cursive]
+version = "0.7.5"
+default-features = false
+features = ["termion-backend"]

src/main.rs

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+extern crate chan;
+extern crate cursive;
+extern crate reqwest;
+extern crate scraper;
+extern crate termion;
+
+use std::process::{Command, Stdio};
+
+use cursive::Cursive;
+use cursive::align::HAlign;
+use cursive::event::{EventResult, Key};
+use cursive::theme::{BaseColor, Color, Theme};
+use cursive::traits::*;
+use cursive::views::{Dialog, EditView, OnEventView, SelectView};
+
+use reqwest::Client;
+
+use scraper::{Html, Selector};
+
+struct SearchResult {
+    title: String,
+    domain: String,
+    url: String,
+}
+
+const DDG_HTML_URL: &str = "https://duckduckgo.com";
+
+fn main() {
+    let mut siv = Cursive::new();
+    siv.add_active_screen();
+
+    let theme = get_dark_theme(&siv);
+    siv.set_theme(theme);
+
+    siv.add_layer(
+        Dialog::new()
+            .title("Ferret")
+            // Padding is (left, right, top, bottom)
+            .padding((1, 1, 1, 0))
+            .content(
+                EditView::new()
+                    .on_submit(search)
+                    .with_id("query")
+                    .fixed_width(50),
+            )
+            .button("Ok", |s| {
+                // This will run the given closure, *ONLY* if a view with the
+                // correct type and the given ID is found.
+                let query = s.call_on_id("query", |view: &mut EditView| {
+                    // We can return content from the closure!
+                    view.get_content()
+                }).unwrap();
+
+                // Run the next step
+                search(s, &query);
+            }),
+    );
+
+    siv.run();
+}
+
+// This will make the search and display results in a new popup.
+// If the query is empty, we'll show an error message instead.
+fn search(s: &mut Cursive, query: &str) {
+    if query.is_empty() {
+        s.add_layer(Dialog::info("Please enter a search query!"));
+    } else {
+        let client = Client::new();
+        let url = format!("{}/html/?q={}", DDG_HTML_URL, query);
+        let mut resp = client.get(&url).send().unwrap();
+        let document = Html::parse_document(&resp.text().unwrap());
+        let result_selector = Selector::parse(".web-result").unwrap();
+        let result_title_selector = Selector::parse(".result__a").unwrap();
+        let result_url_selector = Selector::parse(".result__url").unwrap();
+
+        let mut results: Vec<SearchResult> = Vec::new();
+        for result in document.select(&result_selector) {
+            let result_title = result.select(&result_title_selector).next().unwrap();
+            let result_url = result.select(&result_url_selector).next().unwrap();
+            results.push(SearchResult {
+                title: result_title.text().collect::<Vec<_>>().join(""),
+                domain: result_url.text().collect::<Vec<_>>().join(""),
+                url: String::from(result_url.value().attr("href").unwrap()),
+            } );
+        }
+
+        s.pop_layer();
+        s.add_layer(
+            Dialog::new()
+                .title(query)
+                .button("Exit", |s| s.quit())
+                .content(build_list(results))
+        )
+    }
+}
+
+fn build_list(results: Vec<SearchResult>) -> OnEventView<SelectView> {
+    let mut result_view = SelectView::new().h_align(HAlign::Left);
+
+    for (i, result) in results.into_iter().enumerate() {
+        let url = format!("{}{}", DDG_HTML_URL, result.url);
+        result_view = result_view.item(
+            format!("{}. {}", i, result.title),
+            url.clone()
+        )
+        .item(
+            format!("   {}", result.domain.replace("\n", "").trim()),
+            url.clone()
+        )
+		.item(
+			"   ",
+            url.clone()
+        );
+    }
+
+    result_view.set_on_submit(open_url);
+
+    let result_view = OnEventView::new(result_view)
+        .on_pre_event_inner(Key::Up, |s| {
+            let from_bottom = (s.len() - 1) - s.selected_id().unwrap();
+            if from_bottom < 2 {
+                s.select_up(2 - from_bottom);
+            } else {
+                s.select_up(3);
+            }
+            Some(EventResult::Consumed(None))
+        })
+        .on_pre_event_inner(Key::Down, |s| {
+            if s.selected_id().unwrap() != s.len() - 3 {
+                s.select_down(4);
+                s.select_up(1);
+            }
+            Some(EventResult::Consumed(None))
+        });
+
+    result_view
+}
+
+fn open_url(_: &mut Cursive, url: &str) {
+    Command::new("w3m")
+        .args(&[url])
+        .stdin(Stdio::inherit())
+        .stdout(Stdio::inherit())
+        .output().unwrap();
+}
+
+fn get_dark_theme(siv: &Cursive) -> Theme {
+    // We'll return the current theme with a small modification
+    let mut theme = siv.current_theme().clone();
+
+    theme.colors.background = Color::TerminalDefault;
+    theme.colors.view = Color::Dark(BaseColor::Black);
+    theme.colors.shadow = Color::Dark(BaseColor::Black);
+    theme.colors.primary = Color::Dark(BaseColor::White);
+    theme.colors.tertiary = Color::Dark(BaseColor::Black);
+
+    theme
+}