1 files changed, 105 insertions, 0 deletions
diff --git a/coverage/htmlfiles/coverage_html.js b/coverage/htmlfiles/coverage_html.js
index 7b6db427..10482faf 100644
--- a/coverage/htmlfiles/coverage_html.js
+++ b/coverage/htmlfiles/coverage_html.js
@@ -90,8 +90,17 @@ coverage.pyfile_ready = function($) {
     var frag = location.hash;
     if (frag.length > 2 && frag[1] === 'n') {
         $(frag).addClass('highlight');
+        coverage.sel_begin = parseInt(frag.substr(2));
+        coverage.sel_end = coverage.sel_begin + 1;
     }
 
+    $(document)
+        .bind('keydown', 'j', coverage.to_next_chunk)
+        .bind('keydown', 'k', coverage.to_prev_chunk)
+        .bind('keydown', '0', coverage.to_top)
+        .bind('keydown', '1', coverage.to_first_chunk)
+        ;
+
     coverage.assign_shortkeys();
 };
 
@@ -108,3 +117,99 @@ coverage.toggle_lines = function(btn, cls) {
     }
 };
 
+// The first line selected, and the next line not selected.
+coverage.sel_begin = 0;
+coverage.sel_end = 1;
+
+coverage.to_top = function() {
+    coverage.sel_begin = 0;
+    coverage.sel_end = 1;
+    $("html").animate({scrollTop: 0}, 200);
+};
+
+coverage.to_first_chunk = function() {
+    coverage.sel_begin = 0;
+    coverage.sel_end = 1;
+    coverage.to_next_chunk();
+};
+
+coverage.to_next_chunk = function() {
+    var c = coverage; 
+
+    // Find the start of the next colored chunk.
+    var probe = c.sel_end;
+    while (true) {
+        var probe_line = $("#t" + probe);
+        if (probe_line.length === 0) {
+            return;
+        }
+        var color = probe_line.css("background-color");
+        if (color !== "transparent") {
+            break;
+        }
+        probe += 1;
+    }
+
+    // There's a next chunk, `probe` points to it.
+    c.sel_begin = probe;
+
+    // Find the end of this chunk.
+    var next_color = color;
+    while (next_color === color) {
+        probe += 1;
+        next_color = $("#t" + probe).css("background-color");
+    }
+    c.sel_end = probe;
+    coverage.show_selected_chunk();
+};
+
+coverage.to_prev_chunk = function() {
+    var c = coverage; 
+
+    // Find the end of the prev colored chunk.
+    var probe = c.sel_begin-1;
+    var color = $("#t" + probe).css("background-color");
+    while (probe > 0 && color === "transparent") {
+        probe -= 1;
+        var probe_line = $("#t" + probe);
+        if (probe_line.length === 0) {
+            return;
+        }
+        color = probe_line.css("background-color");
+    }
+
+    // There's a prev chunk, `probe` points to its last line.
+    c.sel_end = probe+1;
+
+    // Find the beginning of this chunk.
+    var prev_color = color;
+    while (prev_color === color) {
+        probe -= 1;
+        prev_color = $("#t" + probe).css("background-color");
+    }
+    c.sel_begin = probe+1;
+    coverage.show_selected_chunk();
+};
+
+coverage.show_selected_chunk = function() {
+    var c = coverage;
+
+    // Highlight the lines in the chunk
+    $(".linenos p").removeClass("highlight");
+    var probe = c.sel_begin;
+    while (probe > 0 && probe < c.sel_end) {
+        $("#n" + probe).addClass("highlight");
+        probe += 1;
+    }
+
+    // Scroll the page if the chunk isn't fully visible.
+    var top = $("#t" + c.sel_begin);
+    var next = $("#t" + c.sel_end);
+
+    if (!top.isOnScreen() || !next.isOnScreen()) {
+        // Need to move the page.
+        var top_pos = parseInt(top.offset().top);
+        $("html").animate({scrollTop: top_pos-30}, 300);
+    }
+};
+