From d7a59810484015eda26ab34938512c54f6477d4e Mon Sep 17 00:00:00 2001
From: Tom Crayford <tcrayford@googlemail.com>
Date: Sun, 8 Jan 2017 21:09:02 +0000
Subject: [PATCH] print glutin events if --print-events is passed

When debugging many issues, it's often very helpful to have the raw
glutin events printed out to stderr as they come in. This does that.

Note that since `glutin::Event` doesn't implement `Display`, we just use
rust's debugging output for now via `{:?}`.
---
 src/cli.rs   | 3 +++
 src/event.rs | 7 +++++++
 src/main.rs  | 1 +
 3 files changed, 11 insertions(+)

diff --git a/src/cli.rs b/src/cli.rs
index e95114c7..8500ebab 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -16,6 +16,7 @@ use index::{Line, Column};
 
 /// Options specified on the command line
 pub struct Options {
+    pub print_events: bool,
     pub ref_test: bool,
     pub columns: Column,
     pub lines: Line,
@@ -25,6 +26,7 @@ pub struct Options {
 impl Default for Options {
     fn default() -> Options {
         Options {
+            print_events: false,
             ref_test: false,
             columns: Column(80),
             lines: Line(24),
@@ -43,6 +45,7 @@ impl Options {
             match &arg[..] {
                 // Generate ref test
                 "--ref-test" => options.ref_test = true,
+                "--print-events" => options.print_events = true,
                 // Set dimensions
                 "-d" | "--dimensions" => {
                     args_iter.next()
diff --git a/src/event.rs b/src/event.rs
index bdfe2708..03d0ef7f 100644
--- a/src/event.rs
+++ b/src/event.rs
@@ -9,6 +9,7 @@ use parking_lot::MutexGuard;
 use glutin::{self, ElementState};
 
 use config::Config;
+use cli::Options;
 use display::OnResize;
 use index::{Line, Column, Side};
 use input::{self, ActionContext, MouseBinding, KeyBinding};
@@ -58,6 +59,7 @@ impl Default for Mouse {
 pub struct Processor<N> {
     key_bindings: Vec<KeyBinding>,
     mouse_bindings: Vec<MouseBinding>,
+    print_events: bool,
     notifier: N,
     mouse: Mouse,
     resize_tx: mpsc::Sender<(u32, u32)>,
@@ -83,6 +85,7 @@ impl<N: Notify> Processor<N> {
     pub fn new(
         notifier: N,
         resize_tx: mpsc::Sender<(u32, u32)>,
+        options: &Options,
         config: &Config,
         ref_test: bool,
         size_info: SizeInfo,
@@ -90,6 +93,7 @@ impl<N: Notify> Processor<N> {
         Processor {
             key_bindings: config.key_bindings().to_vec(),
             mouse_bindings: config.mouse_bindings().to_vec(),
+            print_events: options.print_events,
             notifier: notifier,
             resize_tx: resize_tx,
             ref_test: ref_test,
@@ -184,6 +188,9 @@ impl<N: Notify> Processor<N> {
             // Convenience macro which curries most arguments to handle_event.
             macro_rules! process {
                 ($event:expr) => {
+                    if self.print_events {
+                        err_println!("glutin event: {:?}", $event);
+                    }
                     Processor::handle_event(
                         &mut processor,
                         $event,
diff --git a/src/main.rs b/src/main.rs
index fb305e7c..cda28d13 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -118,6 +118,7 @@ fn run(mut config: Config, options: cli::Options) -> Result<(), Box<Error>> {
     let mut processor = event::Processor::new(
         event_loop::Notifier(loop_tx),
         display.resize_channel(),
+        &options,
         &config,
         options.ref_test,
         display.size().to_owned(),