Add handling for chart axis label position.

.indent.pro

@@ -49,6 +49,7 @@
 -T lxw_cell
 -T lxw_chart
 -T lxw_chart_axis
+-T lxw_chart_axis_label_position
 -T lxw_chart_axis_tick_position
 -T lxw_chart_fill
 -T lxw_chart_font

include/xlsxwriter/chart.h

@@ -436,6 +436,26 @@ typedef enum lxw_chart_axis_tick_position {
     LXW_CHART_AXIS_POSITION_BETWEEN
 } lxw_chart_axis_tick_position;
 
+/**
+ * @brief Axis label positions.
+ */
+typedef enum lxw_chart_axis_label_position {
+
+    /** Position the axis labels next to the axis. The default. */
+    LXW_CHART_AXIS_LABEL_POSITION_NEXT_TO,
+
+    /** Position the axis labels at the top of the chart, for horizontal
+     * axes, or to the right for vertical axes.*/
+    LXW_CHART_AXIS_LABEL_POSITION_HIGH,
+
+    /** Position the axis labels at the bottom of the chart, for horizontal
+     * axes, or to the left for vertical axes.*/
+    LXW_CHART_AXIS_LABEL_POSITION_LOW,
+
+    /** Turn off the the axis labels. */
+    LXW_CHART_AXIS_LABEL_POSITION_NONE
+} lxw_chart_axis_label_position;
+
 enum lxw_chart_position {
     LXW_CHART_AXIS_RIGHT,
     LXW_CHART_AXIS_LEFT,
@@ -666,6 +686,7 @@ typedef struct lxw_chart_axis {
     uint8_t is_date;
     uint8_t is_value;
     uint8_t position_axis;
+    uint8_t label_position;
     uint8_t hidden;
     uint8_t reverse;
     uint8_t has_min;
@@ -1402,6 +1423,43 @@ void chart_axis_off(lxw_chart_axis *axis);
  */
 void chart_axis_set_position(lxw_chart_axis *axis, uint8_t position);
 
+/**
+ * @brief Position the axis labels.
+ *
+ * @param axis     A pointer to a chart #lxw_chart_axis object.
+ * @param position A #lxw_chart_axis_label_position value.
+ *
+ * Position the axis labels for the chart. The labels are the numbers, or
+ * strings or dates, on the axis that indicate the categories or values of
+ * the axis.
+ *
+ * For example:
+ *
+ * @code
+ *     chart_axis_set_label_position(chart->x_axis, LXW_CHART_AXIS_LABEL_POSITION_HIGH);
+       chart_axis_set_label_position(chart->y_axis, LXW_CHART_AXIS_LABEL_POSITION_HIGH);
+ * @endcode
+ *
+ * @image html chart_label_position2.png
+ *
+ * The allowable values:
+ *
+ * - #LXW_CHART_AXIS_LABEL_POSITION_NEXT_TO - The default.
+ * - #LXW_CHART_AXIS_LABEL_POSITION_HIGH - Also right for vertical axes.
+ * - #LXW_CHART_AXIS_LABEL_POSITION_LOW - Also left for vertical axes.
+ * - #LXW_CHART_AXIS_LABEL_POSITION_NONE
+ *
+ * @image html chart_label_position1.png
+ *
+ * The #LXW_CHART_AXIS_LABEL_POSITION_NONE turns off the axis labels. This
+ * is slightly different from `chart_axis_off()` which also turns off the
+ * labels but also turns off tick marks.
+ *
+ * **Axis types**: This function is applicable to to all axes types.
+ *                 See @ref ww_charts_axes.
+ */
+void chart_axis_set_label_position(lxw_chart_axis *axis, uint8_t position);
+
 /**
  * @brief Set the minimum value for a chart axis.
  *

src/chart.c

@@ -2242,14 +2242,21 @@ _chart_write_axis_pos(lxw_chart *self, uint8_t position, uint8_t reverse)
  * Write the <c:tickLblPos> element.
  */
 STATIC void
-_chart_write_tick_lbl_pos(lxw_chart *self)
+_chart_write_tick_label_pos(lxw_chart *self, lxw_chart_axis *axis)
 {
     struct xml_attribute_list attributes;
     struct xml_attribute *attribute;
-    char val[] = "nextTo";
 
     LXW_INIT_ATTRIBUTES();
-    LXW_PUSH_ATTRIBUTES_STR("val", val);
+
+    if (axis->label_position == LXW_CHART_AXIS_LABEL_POSITION_HIGH)
+        LXW_PUSH_ATTRIBUTES_STR("val", "high");
+    else if (axis->label_position == LXW_CHART_AXIS_LABEL_POSITION_LOW)
+        LXW_PUSH_ATTRIBUTES_STR("val", "low");
+    else if (axis->label_position == LXW_CHART_AXIS_LABEL_POSITION_NONE)
+        LXW_PUSH_ATTRIBUTES_STR("val", "none");
+    else
+        LXW_PUSH_ATTRIBUTES_STR("val", "nextTo");
 
     lxw_xml_empty_tag(self->file, "c:tickLblPos", &attributes);
 
@@ -2727,7 +2734,7 @@ _chart_write_cat_axis(lxw_chart *self)
     _chart_write_major_tick_mark(self, self->x_axis);
 
     /* Write the c:tickLblPos element. */
-    _chart_write_tick_lbl_pos(self);
+    _chart_write_tick_label_pos(self, self->x_axis);
 
     /* Write the c:spPr element for the axis line. */
     _chart_write_sp_pr(self, self->x_axis->line, self->x_axis->fill,
@@ -2797,7 +2804,7 @@ _chart_write_val_axis(lxw_chart *self)
     _chart_write_major_tick_mark(self, self->y_axis);
 
     /* Write the c:tickLblPos element. */
-    _chart_write_tick_lbl_pos(self);
+    _chart_write_tick_label_pos(self, self->y_axis);
 
     /* Write the c:spPr element for the axis line. */
     _chart_write_sp_pr(self, self->y_axis->line, self->y_axis->fill,
@@ -2861,7 +2868,7 @@ _chart_write_cat_val_axis(lxw_chart *self)
     _chart_write_major_tick_mark(self, self->x_axis);
 
     /* Write the c:tickLblPos element. */
-    _chart_write_tick_lbl_pos(self);
+    _chart_write_tick_label_pos(self, self->x_axis);
 
     /* Write the c:spPr element for the axis line. */
     _chart_write_sp_pr(self, self->x_axis->line, self->x_axis->fill,
@@ -3944,6 +3951,15 @@ chart_axis_set_position(lxw_chart_axis *axis, uint8_t position)
     axis->position_axis = position;
 }
 
+/*
+ * Set the axis label position.
+ */
+void
+chart_axis_set_label_position(lxw_chart_axis *axis, uint8_t position)
+{
+    axis->label_position = position;
+}
+
 /*
  * Set the minimum value for an axis.
  */

test/functional/src/test_chart_axis19.c

@@ -0,0 +1,45 @@
+/*****************************************************************************
+ * Test cases for libxlsxwriter.
+ *
+ * Test to compare output against Excel files.
+ *
+ * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+ *
+ */
+
+#include "xlsxwriter.h"
+
+int main() {
+
+    lxw_workbook  *workbook  = new_workbook("test_chart_axis19.xlsx");
+    lxw_worksheet *worksheet = workbook_add_worksheet(workbook, NULL);
+    lxw_chart     *chart     = workbook_add_chart(workbook, LXW_CHART_COLUMN);
+
+    /* For testing, copy the randomly generated axis ids in the target file. */
+    chart->axis_id_1 = 43813504;
+    chart->axis_id_2 = 45705472;
+
+    uint8_t data[5][3] = {
+        {1, 2,  3},
+        {2, 4,  6},
+        {3, 6,  9},
+        {4, 8,  12},
+        {5, 10, 15}
+    };
+
+    int row, col;
+    for (row = 0; row < 5; row++)
+        for (col = 0; col < 3; col++)
+            worksheet_write_number(worksheet, row, col, data[row][col], NULL);
+
+    chart_add_series(chart, NULL, "=Sheet1!$A$1:$A$5");
+    chart_add_series(chart, NULL, "=Sheet1!$B$1:$B$5");
+    chart_add_series(chart, NULL, "=Sheet1!$C$1:$C$5");
+
+    chart_axis_set_label_position(chart->x_axis, LXW_CHART_AXIS_LABEL_POSITION_HIGH);
+    chart_axis_set_label_position(chart->y_axis, LXW_CHART_AXIS_LABEL_POSITION_LOW);
+
+    worksheet_insert_chart(worksheet, CELL("E9"), chart);
+
+    return workbook_close(workbook);
+}

test/functional/src/test_chart_axis20.c

@@ -0,0 +1,45 @@
+/*****************************************************************************
+ * Test cases for libxlsxwriter.
+ *
+ * Test to compare output against Excel files.
+ *
+ * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+ *
+ */
+
+#include "xlsxwriter.h"
+
+int main() {
+
+    lxw_workbook  *workbook  = new_workbook("test_chart_axis20.xlsx");
+    lxw_worksheet *worksheet = workbook_add_worksheet(workbook, NULL);
+    lxw_chart     *chart     = workbook_add_chart(workbook, LXW_CHART_COLUMN);
+
+    /* For testing, copy the randomly generated axis ids in the target file. */
+    chart->axis_id_1 = 43572224;
+    chart->axis_id_2 = 43812352;
+
+    uint8_t data[5][3] = {
+        {1, 2,  3},
+        {2, 4,  6},
+        {3, 6,  9},
+        {4, 8,  12},
+        {5, 10, 15}
+    };
+
+    int row, col;
+    for (row = 0; row < 5; row++)
+        for (col = 0; col < 3; col++)
+            worksheet_write_number(worksheet, row, col, data[row][col], NULL);
+
+    chart_add_series(chart, NULL, "=Sheet1!$A$1:$A$5");
+    chart_add_series(chart, NULL, "=Sheet1!$B$1:$B$5");
+    chart_add_series(chart, NULL, "=Sheet1!$C$1:$C$5");
+
+    chart_axis_set_label_position(chart->x_axis, LXW_CHART_AXIS_LABEL_POSITION_NEXT_TO);
+    chart_axis_set_label_position(chart->y_axis, LXW_CHART_AXIS_LABEL_POSITION_NONE);
+
+    worksheet_insert_chart(worksheet, CELL("E9"), chart);
+
+    return workbook_close(workbook);
+}

test/functional/test_chart_axis.py

@@ -56,7 +56,11 @@ class TestCompareXLSXFiles(base_test_class.XLSXBaseTest):
     def test_chart_axis17(self):
         self.run_exe_test('test_chart_axis17')
 
+    def test_chart_axis19(self):
+        self.run_exe_test('test_chart_axis19')
 
+    def test_chart_axis20(self):
+        self.run_exe_test('test_chart_axis20')
 
     def test_chart_axis21(self):
         self.run_exe_test('test_chart_axis21')