Fixes for heatmap panel in Grafana 5 (#10973)

* heatmap: fix chart height

* heatmap: fix font size

* heatmap: fix legend size

* heatmap: fix rendering tests

public/app/plugins/panel/heatmap/color_legend.ts

@@ -8,13 +8,18 @@ import { getColorScale, getOpacityScale } from './color_scale';
 
 let module = angular.module('grafana.directives');
 
+const LEGEND_HEIGHT_PX = 6;
+const LEGEND_WIDTH_PX = 100;
+const LEGEND_TICK_SIZE = 0;
+const LEGEND_VALUE_MARGIN = 0;
+
 /**
  * Color legend for heatmap editor.
  */
 module.directive('colorLegend', function() {
   return {
     restrict: 'E',
-    template: '<div class="heatmap-color-legend"><svg width="16.8rem" height="24px"></svg></div>',
+    template: '<div class="heatmap-color-legend"><svg width="16.5rem" height="24px"></svg></div>',
     link: function(scope, elem, attrs) {
       let ctrl = scope.ctrl;
       let panel = scope.ctrl.panel;
@@ -50,7 +55,7 @@ module.directive('colorLegend', function() {
 module.directive('heatmapLegend', function() {
   return {
     restrict: 'E',
-    template: '<div class="heatmap-color-legend"><svg width="100px" height="14px"></svg></div>',
+    template: `<div class="heatmap-color-legend"><svg width="${LEGEND_WIDTH_PX}px" height="${LEGEND_HEIGHT_PX}px"></svg></div>`,
     link: function(scope, elem, attrs) {
       let ctrl = scope.ctrl;
       let panel = scope.ctrl.panel;
@@ -163,10 +168,10 @@ function drawLegendValues(elem, colorScale, rangeFrom, rangeTo, maxValue, minVal
   let xAxis = d3
     .axisBottom(legendValueScale)
     .tickValues(ticks)
-    .tickSize(2);
+    .tickSize(LEGEND_TICK_SIZE);
 
   let colorRect = legendElem.find(':first-child');
-  let posY = getSvgElemHeight(legendElem) + 2;
+  let posY = getSvgElemHeight(legendElem) + LEGEND_VALUE_MARGIN;
   let posX = getSvgElemX(colorRect);
 
   d3

public/app/plugins/panel/heatmap/rendering.ts

@@ -66,8 +66,7 @@ export default function link(scope, elem, attrs, ctrl) {
         height = parseInt(height.replace('px', ''), 10);
       }
 
-      height -= 5; // padding
-      height -= panel.title ? 24 : 9; // subtract panel title bar
+      height -= panel.legend.show ? 28 : 11; // bottom padding and space for legend
 
       $heatmap.css('height', height + 'px');
 

public/app/plugins/panel/heatmap/specs/renderer_specs.ts

@@ -51,6 +51,9 @@ describe('grafanaHeatmap', function() {
                   colorScheme: 'interpolateOranges',
                   fillBackground: false,
                 },
+                legend: {
+                  show: false,
+                },
                 xBucketSize: 1000,
                 xBucketNumber: null,
                 yBucketSize: 1,

public/sass/components/_panel_heatmap.scss

+$font-size-heatmap-tick: 11px;
+
 .heatmap-canvas-wrapper {
   // position: relative;
   cursor: crosshair;
@@ -10,7 +12,7 @@
     text {
       fill: $text-color;
       color: $text-color;
-      font-size: $font-size-sm;
+      font-size: $font-size-heatmap-tick;
     }
 
     line {
@@ -56,12 +58,12 @@
 .heatmap-legend-wrapper {
   @include clearfix();
   margin: 0 $spacer;
-  padding-top: 10px;
+  padding-top: 4px;
 
   svg {
     width: 100%;
     max-width: 300px;
-    height: 33px;
+    height: 18px;
     float: left;
     white-space: nowrap;
     padding-left: 10px;
@@ -75,7 +77,7 @@
     text {
       fill: $text-color;
       color: $text-color;
-      font-size: $font-size-sm;
+      font-size: $font-size-heatmap-tick;
     }
 
     line {