From f2bbd301f294eaea6755421ff87830cfc1af78b9 Mon Sep 17 00:00:00 2001
From: Michael Carlberg <c@rlberg.se>
Date: Sat, 12 Nov 2016 09:40:14 +0100
Subject: [PATCH] feat(xbacklight): Change value on scroll

- Add action handlers for scroll up/down (conf: enable-sroll = true)
- Use xcb_timestamps instead of the throttle util
---
 include/common.hpp             |   1 +
 include/modules/xbacklight.hpp |  13 ++++-
 include/x11/graphics.hpp       |   8 ++-
 include/x11/randr.hpp          |   1 +
 src/components/eventloop.cpp   |   2 +-
 src/modules/xbacklight.cpp     |  99 +++++++++++++++++++++++++------
 src/x11/graphics.cpp           | 103 ++++++++++++++++++++++-----------
 src/x11/randr.cpp              |  27 +++++----
 8 files changed, 184 insertions(+), 70 deletions(-)

diff --git a/include/common.hpp b/include/common.hpp
index e726a9db..b3153e95 100644
--- a/include/common.hpp
+++ b/include/common.hpp
@@ -68,6 +68,7 @@ using std::to_string;
 using std::strerror;
 using std::getenv;
 using std::thread;
+using std::exception;
 
 using boost::optional;
 
diff --git a/include/modules/xbacklight.hpp b/include/modules/xbacklight.hpp
index 12e00fa2..bc51d640 100644
--- a/include/modules/xbacklight.hpp
+++ b/include/modules/xbacklight.hpp
@@ -9,7 +9,6 @@
 #include "drawtypes/progressbar.hpp"
 #include "drawtypes/ramp.hpp"
 #include "modules/meta.hpp"
-#include "utils/throttle.hpp"
 
 LEMONBUDDY_NS
 
@@ -35,21 +34,31 @@ namespace modules {
     void setup();
     void handle(const evt::randr_notify& evt);
     void update();
+    string get_output();
     bool build(builder* builder, string tag) const;
+    bool handle_event(string cmd);
+    bool receive_events() const {
+      return true;
+    }
 
    private:
     static constexpr auto TAG_LABEL = "<label>";
     static constexpr auto TAG_BAR = "<bar>";
     static constexpr auto TAG_RAMP = "<ramp>";
 
-    throttle_util::throttle_t m_throttler;
+    static constexpr auto EVENT_SCROLLUP = "xbacklight+";
+    static constexpr auto EVENT_SCROLLDOWN = "xbacklight-";
+
     connection& m_connection{configure_connection().create<connection&>()};
     monitor_t m_output;
+    xcb_window_t m_proxy;
+    xcb_timestamp_t m_timestamp;
 
     ramp_t m_ramp;
     label_t m_label;
     progressbar_t m_progressbar;
 
+    bool m_scroll = true;
     int m_percentage = 0;
   };
 }
diff --git a/include/x11/graphics.hpp b/include/x11/graphics.hpp
index 013abce4..888c601d 100644
--- a/include/x11/graphics.hpp
+++ b/include/x11/graphics.hpp
@@ -18,10 +18,12 @@ namespace graphics_util {
     xcb_pixmap_t pixmap{0};
   };
 
-  void get_root_pixmap(connection& conn, root_pixmap* rpix);
+  bool create_window(connection& conn, xcb_window_t* win, int16_t x = 0, int16_t y = 0, uint16_t w = 1, uint16_t h = 1);
+  bool create_pixmap(connection& conn, xcb_drawable_t dst, uint16_t w, uint16_t h, xcb_pixmap_t* pixmap);
+  bool create_pixmap(connection& conn, xcb_drawable_t dst, uint16_t w, uint16_t h, uint8_t d, xcb_pixmap_t* pixmap);
+  bool create_gc(connection& conn, xcb_drawable_t drawable, xcb_gcontext_t* gc);
 
-  void simple_gc(connection& conn, xcb_drawable_t drawable, xcb_gcontext_t* gc);
-  void simple_pixmap(connection& conn, xcb_window_t dst, int w, int h, xcb_pixmap_t* pixmap);
+  bool get_root_pixmap(connection& conn, root_pixmap* rpix);
 }
 
 LEMONBUDDY_NS_END
diff --git a/include/x11/randr.hpp b/include/x11/randr.hpp
index 530d7d28..349f30f7 100644
--- a/include/x11/randr.hpp
+++ b/include/x11/randr.hpp
@@ -13,6 +13,7 @@
 LEMONBUDDY_NS
 
 struct backlight_values {
+  uint32_t atom = 0;
   uint32_t min = 0;
   uint32_t max = 0;
   uint32_t val = 0;
diff --git a/src/components/eventloop.cpp b/src/components/eventloop.cpp
index 8ac26932..c307e883 100644
--- a/src/components/eventloop.cpp
+++ b/src/components/eventloop.cpp
@@ -61,7 +61,7 @@ void eventloop::run(chrono::duration<double, std::milli> timeframe, int limit) {
           evt = next;
           break;
         } else if (compare_events(evt, next)) {
-          m_log.trace("eventloop: Swallowing event within timeframe");
+          m_log.trace_x("eventloop: Swallowing event within timeframe");
           evt = next;
         } else {
           break;
diff --git a/src/modules/xbacklight.cpp b/src/modules/xbacklight.cpp
index 787f06f8..61eb7697 100644
--- a/src/modules/xbacklight.cpp
+++ b/src/modules/xbacklight.cpp
@@ -1,5 +1,6 @@
 #include "modules/xbacklight.hpp"
 #include "utils/math.hpp"
+#include "x11/graphics.hpp"
 
 LEMONBUDDY_NS
 
@@ -23,26 +24,27 @@ namespace modules {
       throw module_error("No matching output found for \"" + output + "\", stopping module...");
     }
 
+    // Get flag to check if we should add scroll handlers for changing value
+    GET_CONFIG_VALUE(name(), m_scroll, "enable-scroll");
+
     // Query randr for the backlight max and min value
     try {
       auto& backlight = m_output->backlight;
       randr_util::get_backlight_range(m_connection, m_output, backlight);
       randr_util::get_backlight_value(m_connection, m_output, backlight);
-    } catch (const std::exception& err) {
+    } catch (const exception& err) {
       throw module_error("No backlight data found for \"" + output + "\", stopping module...");
     }
 
-    // Connect with the event registry and tell randr that we
-    // want to get notified when an output property gets modified
-    m_connection.attach_sink(this, 1);
-    m_connection.select_input_checked(
-        m_connection.screen()->root, XCB_RANDR_NOTIFY_MASK_OUTPUT_PROPERTY);
+    // Create window that will proxy all RandR notify events
+    if (!graphics_util::create_window(m_connection, &m_proxy, -1, -1, 1, 1)) {
+      throw module_error("Failed to create event proxy");
+    }
 
-    // Create a throttle so that we limit the amount of events
-    // to handle since randr can burst out quite a few
-    // We will allow 1 event per 60 ms. The updates still look smooth
-    // using this setting which is important.
-    m_throttler = throttle_util::make_throttler(1, 60ms);
+    // Connect with the event registry and make sure we get
+    // notified when a RandR output property gets modified
+    m_connection.attach_sink(this, 1);
+    m_connection.select_input_checked(m_proxy, XCB_RANDR_NOTIFY_MASK_OUTPUT_PROPERTY);
 
     // Add formats and elements
     m_formatter->add(DEFAULT_FORMAT, TAG_LABEL, {TAG_LABEL, TAG_BAR, TAG_RAMP});
@@ -64,22 +66,28 @@ namespace modules {
   void xbacklight_module::handle(const evt::randr_notify& evt) {
     if (evt->subCode != XCB_RANDR_NOTIFY_OUTPUT_PROPERTY)
       return;
+    else if (evt->u.op.status != XCB_PROPERTY_NEW_VALUE)
+      return;
+    else if (evt->u.op.window != m_proxy)
+      return;
     else if (evt->u.op.output != m_output->randr_output)
       return;
-    else if (evt->u.op.atom == Backlight)
-      update();
-    else if (evt->u.op.atom == BACKLIGHT)
-      update();
+    else if (evt->u.op.atom != m_output->backlight.atom)
+      return;
+    else if (evt->u.op.timestamp <= m_timestamp)
+      return;
+
+    // Store the timestamp with a throttle offset (ms)
+    m_timestamp = evt->u.op.timestamp + 50;
+
+    // Fetch the new values
+    update();
   }
 
   /**
    * Query the RandR extension for the new values
    */
   void xbacklight_module::update() {
-    // Test if we are allowed to handle the event
-    if (!m_throttler->passthrough(throttle_util::strategy::try_once_or_leave_yolo{}))
-      return;
-
     // Query for the new backlight value
     auto& bl = m_output->backlight;
     randr_util::get_backlight_value(m_connection, m_output, bl);
@@ -96,6 +104,29 @@ namespace modules {
     broadcast();
   }
 
+  /**
+   * Generate the module output
+   */
+  string xbacklight_module::get_output() {
+    if (m_scroll) {
+      if (m_percentage < 100)
+        m_builder->cmd(mousebtn::SCROLL_UP, EVENT_SCROLLUP);
+      if (m_percentage > 0)
+        m_builder->cmd(mousebtn::SCROLL_DOWN, EVENT_SCROLLDOWN);
+
+      m_builder->node(static_module::get_output());
+
+      if (m_percentage < 100)
+        m_builder->cmd_close(true);
+      if (m_percentage > 0)
+        m_builder->cmd_close(true);
+    } else {
+      m_builder->node(static_module::get_output());
+    }
+
+    return m_builder->flush();
+  }
+
   /**
    * Output content as defined in the config
    */
@@ -110,6 +141,36 @@ namespace modules {
       return false;
     return true;
   }
+
+  /**
+   * Process scroll events by changing backlight value
+   */
+  bool xbacklight_module::handle_event(string cmd) {
+    int value_mod = 0;
+
+    if (cmd == EVENT_SCROLLUP) {
+      value_mod = 10;
+      m_log.info("%s: Increasing value by %i%", name(), value_mod);
+    } else if (cmd == EVENT_SCROLLDOWN) {
+      value_mod = -10;
+      m_log.info("%s: Decreasing value by %i%", name(), -value_mod);
+    } else {
+      return false;
+    }
+
+    try {
+      const int new_perc = math_util::cap(m_percentage + value_mod, 0, 100);
+      const int new_value = math_util::percentage_to_value<int>(new_perc, m_output->backlight.max);
+      const int values[1]{new_value};
+
+      m_connection.change_output_property_checked(
+          m_output->randr_output, m_output->backlight.atom, XCB_ATOM_INTEGER, 32, XCB_PROP_MODE_REPLACE, 1, values);
+    } catch (const exception& err) {
+      m_log.err("%s: %s", name(), err.what());
+    }
+
+    return true;
+  }
 }
 
 LEMONBUDDY_NS_END
diff --git a/src/x11/graphics.cpp b/src/x11/graphics.cpp
index 1f91f17d..2f6147d1 100644
--- a/src/x11/graphics.cpp
+++ b/src/x11/graphics.cpp
@@ -9,10 +9,73 @@
 LEMONBUDDY_NS
 
 namespace graphics_util {
+  /**
+   * Create a basic window
+   */
+  bool create_window(connection& conn, xcb_window_t* win, int16_t x, int16_t y, uint16_t w, uint16_t h) {
+    try {
+      auto root = conn.screen()->root;
+      auto copy = XCB_COPY_FROM_PARENT;
+      *win = conn.generate_id();
+      conn.create_window_checked(copy, *win, root, x, y, w, h, 0, copy, copy, 0, nullptr);
+      return true;
+    } catch (const exception& err) {
+      *win = XCB_NONE;
+    }
+
+    return false;
+  }
+
+  /**
+   * Create a basic pixmap with the same depth as the
+   * root depth of the default screen
+   */
+  bool create_pixmap(connection& conn, xcb_drawable_t dst, uint16_t w, uint16_t h, xcb_pixmap_t* pixmap) {
+    return graphics_util::create_pixmap(conn, dst, w, h, conn.screen()->root_depth, pixmap);
+  }
+
+  /**
+   * Create a basic pixmap with specific depth
+   */
+  bool create_pixmap(connection& conn, xcb_drawable_t dst, uint16_t w, uint16_t h, uint8_t d, xcb_pixmap_t* pixmap) {
+    try {
+      *pixmap = conn.generate_id();
+      conn.create_pixmap_checked(d, *pixmap, dst, w, h);
+      return true;
+    } catch (const exception& err) {
+      *pixmap = XCB_NONE;
+    }
+
+    return false;
+  }
+
+  /**
+   * Create a basic gc
+   */
+  bool create_gc(connection& conn, xcb_drawable_t drawable, xcb_gcontext_t* gc) {
+    try {
+      xcb_params_gc_t params;
+
+      uint32_t mask = 0;
+      uint32_t values[32];
+
+      XCB_AUX_ADD_PARAM(&mask, &params, graphics_exposures, false);
+      xutils::pack_values(mask, &params, values);
+
+      *gc = conn.generate_id();
+      conn.create_gc_checked(*gc, drawable, mask, values);
+      return true;
+    } catch (const exception& err) {
+      *gc = XCB_NONE;
+    }
+
+    return false;
+  }
+
   /**
    * Query for the root window pixmap
    */
-  void get_root_pixmap(connection& conn, root_pixmap* rpix) {
+  bool get_root_pixmap(connection& conn, root_pixmap* rpix) {
     auto screen = conn.screen();
     const xcb_atom_t pixmap_properties[3]{ESETROOT_PMAP_ID, _XROOTMAP_ID, _XSETROOT_ID};
     for (auto&& property : pixmap_properties) {
@@ -25,15 +88,15 @@ namespace graphics_util {
     }
 
     if (!rpix->pixmap) {
-      return;
+      return false;
     }
 
     auto cookie = xcb_get_geometry(conn, rpix->pixmap);
     auto reply = xcb_get_geometry_reply(conn, cookie, nullptr);
 
     if (!reply) {
-      rpix->pixmap = 0;
-      return;
+      rpix->pixmap = XCB_NONE;
+      return false;
     }
 
     rpix->depth = reply->depth;
@@ -41,38 +104,8 @@ namespace graphics_util {
     rpix->height = reply->height;
     rpix->x = reply->x;
     rpix->y = reply->y;
-  }
 
-  /**
-   * Create a basic gc
-   */
-  void simple_gc(connection& conn, xcb_drawable_t drawable, xcb_gcontext_t* gc) {
-    xcb_params_gc_t params;
-
-    uint32_t mask = 0;
-    uint32_t values[32];
-
-    XCB_AUX_ADD_PARAM(&mask, &params, graphics_exposures, false);
-    xutils::pack_values(mask, &params, values);
-
-    try {
-      *gc = conn.generate_id();
-      conn.create_gc_checked(*gc, drawable, mask, values);
-    } catch (const std::exception& err) {
-      // no-op
-    }
-  }
-
-  /**
-   * Create a basic pixmap
-   */
-  void simple_pixmap(connection& conn, xcb_window_t dst, int w, int h, xcb_pixmap_t* pixmap) {
-    try {
-      *pixmap = conn.generate_id();
-      conn.create_pixmap_checked(conn.screen()->root_depth, *pixmap, dst, w, h);
-    } catch (const std::exception& err) {
-      // no-op
-    }
+    return true;
   }
 }
 
diff --git a/src/x11/randr.cpp b/src/x11/randr.cpp
index 98e4d0b0..08cb3d0c 100644
--- a/src/x11/randr.cpp
+++ b/src/x11/randr.cpp
@@ -53,34 +53,41 @@ namespace randr_util {
    * Get backlight value range for given output
    */
   void get_backlight_range(connection& conn, const monitor_t& mon, backlight_values& dst) {
-    auto reply = conn.query_output_property(mon->randr_output, Backlight);
+    auto atom = Backlight;
+    auto reply = conn.query_output_property(mon->randr_output, atom);
 
     dst.min = 0;
     dst.max = 0;
 
-    if (!reply->range || reply->length != 2)
-      reply = conn.query_output_property(mon->randr_output, BACKLIGHT);
-    if (!reply->range || reply->length != 2)
+    if (!reply->range || reply->length != 2) {
+      atom = BACKLIGHT;
+      reply = conn.query_output_property(mon->randr_output, atom);
+    }
+
+    if (!reply->range || reply->length != 2) {
       return;
+    }
 
     auto range = reply.valid_values().begin();
-
     dst.min = static_cast<uint32_t>(*range++);
     dst.max = static_cast<uint32_t>(*range);
+    dst.atom = atom;
   }
 
   /**
    * Get backlight value for given output
    */
   void get_backlight_value(connection& conn, const monitor_t& mon, backlight_values& dst) {
-    auto reply = conn.get_output_property(mon->randr_output, Backlight, XCB_ATOM_NONE, 0, 4, 0, 0);
+    dst.val = 0;
+
+    if (!dst.atom) {
+      return;
+    }
+
+    auto reply = conn.get_output_property(mon->randr_output, dst.atom, XCB_ATOM_NONE, 0, 4, 0, 0);
 
-    if (reply->num_items != 1 || reply->format != 32 || reply->type != XCB_ATOM_INTEGER)
-      reply = conn.get_output_property(mon->randr_output, BACKLIGHT, XCB_ATOM_NONE, 0, 4, 0, 0);
     if (reply->num_items == 1 && reply->format == 32 && reply->type == XCB_ATOM_INTEGER)
       dst.val = *reinterpret_cast<uint32_t*>(xcb_randr_get_output_property_data(reply.get().get()));
-    else
-      dst.val = 0;
   }
 }