Introduce GaugeGraphView, allow colouring via styles

There's some fractional improvements in reduced array allocation etc,
but mostly this change is just to remove the duplication of the
graph-generating code that was in TrafficListFragment & GaugeViewHolder.

app/res/layout/gauge_list_item.xml

@@ -82,12 +82,12 @@
         </LinearLayout>
     </LinearLayout>
 
-    <LinearLayout
-        android:id="@+id/ll_bars"
+    <com.github.mobile.gauges.ui.GaugeGraphView
+        android:id="@+id/gauge_graph"
+        style="@style/GaugeGraphDark"
         android:layout_width="0dp"
         android:layout_height="fill_parent"
         android:layout_weight="25"
-        android:minHeight="20dp" >
-    </LinearLayout>
+        android:minHeight="20dp" />
 
 </LinearLayout>

app/res/layout/traffic_graph.xml

@@ -23,10 +23,10 @@
     android:paddingRight="10dp"
     android:paddingTop="10dp" >
 
-    <LinearLayout
-        android:id="@+id/ll_bars"
+    <com.github.mobile.gauges.ui.GaugeGraphView
+        android:id="@+id/gauge_graph"
+        style="@style/GaugeGraphLight"
         android:layout_width="fill_parent"
-        android:layout_height="120dp" >
-    </LinearLayout>
+        android:layout_height="120dp" />
 
 </LinearLayout>

app/res/values/attrs.xml

@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ Copyright 2012 GitHub Inc.
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~  http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  -->
+
+<resources>
+    <declare-styleable name="GaugeGraphView">
+        <attr name="viewsWeekdayColor" format="color" />
+        <attr name="peopleWeekdayColor" format="color" />
+        <attr name="viewsWeekendColor" format="color" />
+        <attr name="peopleWeekendColor" format="color" />
+    </declare-styleable>
+</resources>

app/res/values/colors.xml

@@ -26,17 +26,9 @@
     <color name="pager_background">#F4F4F4</color>
     <color name="pager_background_alternate">#E7E7E7</color>
     <color name="text_link">#20A465</color>
-    <color name="graph_views_weekday">#53685E</color>
-    <color name="graph_people_weekday">#6E9180</color>
-    <color name="graph_views_weekend">#3F544C</color>
-    <color name="graph_people_weekend">#5B796B</color>
     <color name="table_text">#484848</color>
     <color name="table_text_light">#A6A6A6</color>
     <color name="table_text_header">#636363</color>
-    <color name="traffic_views_weekday">#BADDCC</color>
-    <color name="traffic_people_weekday">#97CCB1</color>
-    <color name="traffic_views_weekend">#D1E6DC</color>
-    <color name="traffic_people_weekend">#BBDDCC</color>
     <color name="gauge_background_start">#373737</color>
     <color name="gauge_background_end">#272727</color>
     <color name="header_background_start">#ECECEC</color>

app/res/values/styles.xml

@@ -59,4 +59,17 @@
         <item name="android:includeFontPadding">false</item>
     </style>
 
+    <style name="GaugeGraphDark">
+        <item name="viewsWeekdayColor">#53685E</item>
+        <item name="peopleWeekdayColor">#6E9180</item>
+        <item name="viewsWeekendColor">#3F544C</item>
+        <item name="peopleWeekendColor">#5B796B</item>
+    </style>
+
+    <style name="GaugeGraphLight">
+        <item name="viewsWeekdayColor">#BADDCC</item>
+        <item name="peopleWeekdayColor">#97CCB1</item>
+        <item name="viewsWeekendColor">#D1E6DC</item>
+        <item name="peopleWeekendColor">#BBDDCC</item>
+    </style>
 </resources>

app/src/main/java/com/github/mobile/gauges/ui/GaugeGraphView.java

@@ -0,0 +1,103 @@
+/*
+ * Copyright 2012 GitHub Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.github.mobile.gauges.ui;
+
+import static com.github.mobile.gauges.R.styleable.GaugeGraphView_peopleWeekdayColor;
+import static com.github.mobile.gauges.R.styleable.GaugeGraphView_peopleWeekendColor;
+import static com.github.mobile.gauges.R.styleable.GaugeGraphView_viewsWeekdayColor;
+import static com.github.mobile.gauges.R.styleable.GaugeGraphView_viewsWeekendColor;
+import static java.util.Calendar.DAY_OF_WEEK;
+import static java.util.Calendar.DAY_OF_YEAR;
+import static java.util.Calendar.SATURDAY;
+import static java.util.Calendar.SUNDAY;
+import android.content.Context;
+import android.content.res.TypedArray;
+import android.util.AttributeSet;
+import android.widget.LinearLayout;
+
+import com.github.mobile.gauges.R;
+import com.github.mobile.gauges.core.DatedViewSummary;
+
+import java.util.GregorianCalendar;
+import java.util.List;
+
+/**
+ * A styleable graph that shows the recent traffic for a gauge.
+ */
+public class GaugeGraphView extends LinearLayout {
+
+    private static final long[] NO_TRAFFIC = new long[] { 0, 0 };
+
+    private final int[] weekdayColors, weekendColors;
+
+    private long[][] data;
+
+    private int[][] colors;
+
+    public GaugeGraphView(Context ctx, AttributeSet attrs) {
+        super(ctx, attrs);
+        TypedArray array = ctx.obtainStyledAttributes(attrs, R.styleable.GaugeGraphView);
+
+        weekdayColors = new int[] { array.getColor(GaugeGraphView_viewsWeekdayColor, 0),
+                array.getColor(GaugeGraphView_peopleWeekdayColor, 0) };
+        weekendColors = new int[] { array.getColor(GaugeGraphView_viewsWeekendColor, 0),
+                array.getColor(GaugeGraphView_peopleWeekendColor, 0) };
+
+        array.recycle();
+    }
+
+    /**
+     * This should be set before the graph is updated with traffic data, and will not take
+     * effect until {@link #updateGraphWith(List<DatedViewSummary>)} is called.
+     *
+     * @param numDays the number of days to display in the graph, 1 bar per day
+     */
+    public void setNumDays(int numDays) {
+        data = new long[numDays][];
+        colors = new int[numDays][];
+    }
+
+    /**
+     * Updates the graph to display the supplied data, which will be padded or truncated
+     * to match the number of days specifed with {@link #setNumDays(int)}.
+     *
+     * @param trafficData a list of traffic data by day in reverse-chronological order
+     */
+    public void updateGraphWith(List<DatedViewSummary> trafficData) {
+        setBackgroundDrawable(createBarGraphDrawableFor(trafficData));
+    }
+
+    private BarGraphDrawable createBarGraphDrawableFor(List<DatedViewSummary> daySummaries) {
+        GregorianCalendar calendar = new GregorianCalendar();
+        int daySummaryIndex = 0;
+        for (int barIndex = data.length - 1; barIndex >= 0; --barIndex) {
+            if (daySummaryIndex < daySummaries.size()) {
+                DatedViewSummary day = daySummaries.get(daySummaryIndex);
+                calendar.setTime(day.getDate()); // take date from day summary returned by API
+                data[barIndex] = new long[] { day.getViews(), day.getPeople() };
+            } else {
+                calendar.add(DAY_OF_YEAR, -1); // this bar is for the day before that of the prior iteration
+                data[barIndex] = NO_TRAFFIC; // the API returned no traffic data for this day
+            }
+
+            int dayOfWeek = calendar.get(DAY_OF_WEEK);
+            colors[barIndex] = (dayOfWeek == SATURDAY || dayOfWeek == SUNDAY) ? weekendColors : weekdayColors;
+            ++daySummaryIndex;
+        }
+        return new BarGraphDrawable(data, colors);
+    }
+}

app/src/main/java/com/github/mobile/gauges/ui/GaugeListFragment.java

@@ -20,6 +20,8 @@
 import static com.github.mobile.gauges.IntentConstants.GAUGES;
 import static com.github.mobile.gauges.IntentConstants.VIEW_AIR_TRAFFIC;
 import static com.github.mobile.gauges.IntentConstants.VIEW_GAUGE;
+import static com.madgag.android.listviews.ReflectiveHolderFactory.reflectiveFactoryFor;
+import static com.madgag.android.listviews.ViewInflator.viewInflatorFor;
 import android.content.Intent;
 import android.os.Bundle;
 import android.support.v4.content.Loader;
@@ -33,9 +35,7 @@
 import com.github.mobile.gauges.R.layout;
 import com.github.mobile.gauges.core.Gauge;
 import com.google.inject.Inject;
-import com.madgag.android.listviews.ReflectiveHolderFactory;
 import com.madgag.android.listviews.ViewHoldingListAdapter;
-import com.madgag.android.listviews.ViewInflator;
 
 import java.io.Serializable;
 import java.util.List;
@@ -82,9 +82,8 @@ public void onListItemClick(ListView list, View view, int position, long id) {
 
     @Override
     protected ViewHoldingListAdapter<Gauge> adapterFor(List<Gauge> items) {
-        return new ViewHoldingListAdapter<Gauge>(items, ViewInflator.viewInflatorFor(getActivity(),
-                layout.gauge_list_item), ReflectiveHolderFactory.reflectiveFactoryFor(GaugeViewHolder.class,
-                getActivity().getResources()));
+        return new ViewHoldingListAdapter<Gauge>(items, viewInflatorFor(getActivity(), layout.gauge_list_item),
+                reflectiveFactoryFor(GaugeViewHolder.class));
     }
 
     @Override

app/src/main/java/com/github/mobile/gauges/ui/GaugeViewHolder.java

@@ -16,23 +16,15 @@
 
 package com.github.mobile.gauges.ui;
 
-import static java.util.Calendar.DAY_OF_WEEK;
-import static java.util.Calendar.DAY_OF_YEAR;
-import static java.util.Calendar.SATURDAY;
-import static java.util.Calendar.SUNDAY;
-import android.content.res.Resources;
 import android.view.View;
-import android.widget.LinearLayout;
 import android.widget.TextView;
 
-import com.github.mobile.gauges.R.color;
 import com.github.mobile.gauges.R.id;
 import com.github.mobile.gauges.core.DatedViewSummary;
 import com.github.mobile.gauges.core.Gauge;
 import com.madgag.android.listviews.ViewHolder;
 
 import java.text.NumberFormat;
-import java.util.GregorianCalendar;
 
 /**
  * View holder for a {@link Gauge}
@@ -47,33 +39,19 @@ public class GaugeViewHolder implements ViewHolder<Gauge> {
 
     private final TextView peopleText;
 
-    private final LinearLayout barGraph;
-
-    private final int[] weekendColors;
-
-    private final int[] weekdayColors;
-
-    private final long[][] data;
-
-    private final int[][] colors;
+    private final GaugeGraphView barGraph;
 
     /**
      * Create view holder
      *
      * @param view
-     * @param resources
      */
-    public GaugeViewHolder(final View view, final Resources resources) {
+    public GaugeViewHolder(final View view) {
         nameText = (TextView) view.findViewById(id.tv_gauge_name);
         viewsText = (TextView) view.findViewById(id.tv_gauge_views);
         peopleText = (TextView) view.findViewById(id.tv_gauge_people);
-        barGraph = (LinearLayout) view.findViewById(id.ll_bars);
-        data = new long[7][];
-        colors = new int[7][];
-        weekdayColors = new int[] { resources.getColor(color.graph_views_weekday),
-                resources.getColor(color.graph_people_weekday) };
-        weekendColors = new int[] { resources.getColor(color.graph_views_weekend),
-                resources.getColor(color.graph_people_weekend) };
+        barGraph = (GaugeGraphView) view.findViewById(id.gauge_graph);
+        barGraph.setNumDays(7);
     }
 
     public void updateViewFor(final Gauge gauge) {
@@ -88,31 +66,7 @@ public void updateViewFor(final Gauge gauge) {
 
         viewsText.setText(NUMBER_FORMAT.format(viewsToday));
         peopleText.setText(NUMBER_FORMAT.format(peopleToday));
-        int index = data.length - 1;
-        GregorianCalendar calendar = new GregorianCalendar();
-        for (DatedViewSummary day : gauge.getRecentDays()) {
-            data[index] = new long[] { day.getViews(), day.getPeople() };
-            calendar.setTime(day.getDate());
-            int dayOfWeek = calendar.get(DAY_OF_WEEK);
-            if (dayOfWeek == SATURDAY || dayOfWeek == SUNDAY)
-                colors[index] = weekendColors;
-            else
-                colors[index] = weekdayColors;
-            index--;
-            if (index < 0)
-                break;
-        }
-        // Fill in any days left if recent days reported less than 7
-        while (index >= 0) {
-            data[index] = new long[] { 0, 0 };
-            calendar.add(DAY_OF_YEAR, -1);
-            int dayOfWeek = calendar.get(DAY_OF_WEEK);
-            if (dayOfWeek == SATURDAY || dayOfWeek == SUNDAY)
-                colors[index] = weekendColors;
-            else
-                colors[index] = weekdayColors;
-            index--;
-        }
-        barGraph.setBackgroundDrawable(new BarGraphDrawable(data, colors));
+        barGraph.updateGraphWith(gauge.getRecentDays());
     }
+
 }