Added option to set chart axis horizontal position.

.indent.pro

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

include/xlsxwriter/chart.h

@@ -422,10 +422,18 @@ enum lxw_chart_grouping {
     LXW_GROUPING_STACKED
 };
 
-enum lxw_chart_axis_tick_position {
-    LXW_CHART_AXIS_POSITION_BETWEEN,
-    LXW_CHART_AXIS_POSITION_ON_TICK
-};
+/**
+ * @brief Axis positions for category axes.
+ */
+typedef enum lxw_chart_axis_tick_position {
+    LXW_CHART_AXIS_POSITION_DEFAULT,
+
+    /** Position category axis on tick marks. */
+    LXW_CHART_AXIS_POSITION_ON_TICK,
+
+    /** Position category axis between tick marks. */
+    LXW_CHART_AXIS_POSITION_BETWEEN
+} lxw_chart_axis_tick_position;
 
 enum lxw_chart_position {
     LXW_CHART_AXIS_RIGHT,
@@ -653,6 +661,8 @@ typedef struct lxw_chart_axis {
     lxw_chart_fill *fill;
     lxw_chart_pattern *pattern;
 
+    uint8_t is_category;
+    uint8_t position_axis;
     uint8_t hidden;
     uint8_t reverse;
     uint8_t has_min;
@@ -716,7 +726,7 @@ typedef struct lxw_chart {
     int series_overlap_1;
 
     uint8_t grouping;
-    uint8_t cross_between;
+    uint8_t default_cross_between;
     uint8_t cat_axis_position;
     uint8_t val_axis_position;
 
@@ -1342,6 +1352,29 @@ void chart_axis_set_reverse(lxw_chart_axis *axis);
  */
 void chart_axis_off(lxw_chart_axis *axis);
 
+/**
+ * @brief Position the axis on or between the axis tick marks.
+ *
+ * @param axis     A pointer to a chart #lxw_chart_axis object.
+ * @param position A #lxw_chart_axis_tick_position value.
+ *
+ * Position a category axis horizontally on, or between, the axis tick marks.
+ *
+ * There are two allowable values:
+ *
+ * - #LXW_CHART_AXIS_POSITION_ON_TICK
+ * - #LXW_CHART_AXIS_POSITION_BETWEEN
+ *
+ * @code
+ *     chart_axis_set_position(chart->x_axis, LXW_CHART_AXIS_POSITION_BETWEEN);
+ * @endcode
+ *
+ * @image html chart_axis_set_position.png
+ *
+ * Applicable to category axes only.
+ */
+void chart_axis_set_position(lxw_chart_axis *axis, uint8_t position);
+
 /**
  * @brief Set the minimum value for a chart axis.
  *

src/chart.c

@@ -2406,14 +2406,17 @@ _chart_write_number_format(lxw_chart *self, lxw_chart_axis *axis)
  * Write the <c:crossBetween> element.
  */
 STATIC void
-_chart_write_cross_between(lxw_chart *self)
+_chart_write_cross_between(lxw_chart *self, uint8_t position)
 {
     struct xml_attribute_list attributes;
     struct xml_attribute *attribute;
 
+    if (!position)
+        position = self->default_cross_between;
+
     LXW_INIT_ATTRIBUTES();
 
-    if (self->cross_between)
+    if (position == LXW_CHART_AXIS_POSITION_ON_TICK)
         LXW_PUSH_ATTRIBUTES_STR("val", "midCat");
     else
         LXW_PUSH_ATTRIBUTES_STR("val", "between");
@@ -2803,7 +2806,7 @@ _chart_write_val_axis(lxw_chart *self)
     _chart_write_crosses(self);
 
     /* Write the c:crossBetween element. */
-    _chart_write_cross_between(self);
+    _chart_write_cross_between(self, self->x_axis->position_axis);
 
     lxw_xml_end_tag(self->file, "c:valAx");
 }
@@ -2867,7 +2870,7 @@ _chart_write_cat_val_axis(lxw_chart *self)
     _chart_write_crosses(self);
 
     /* Write the c:crossBetween element. */
-    _chart_write_cross_between(self);
+    _chart_write_cross_between(self, self->y_axis->position_axis);
 
     lxw_xml_end_tag(self->file, "c:valAx");
 }
@@ -3233,7 +3236,8 @@ STATIC void
 _chart_initialize_area_chart(lxw_chart *self, uint8_t type)
 {
     self->grouping = LXW_GROUPING_STANDARD;
-    self->cross_between = LXW_CHART_AXIS_POSITION_ON_TICK;
+    self->default_cross_between = LXW_CHART_AXIS_POSITION_ON_TICK;
+    self->x_axis->is_category = LXW_TRUE;
 
     if (type == LXW_CHART_AREA_STACKED) {
         self->grouping = LXW_GROUPING_STACKED;
@@ -3267,6 +3271,7 @@ _chart_initialize_bar_chart(lxw_chart *self, uint8_t type)
     /*Also reverse some of the defaults. */
     self->x_axis->major_gridlines.visible = LXW_FALSE;
     self->y_axis->major_gridlines.visible = LXW_TRUE;
+    self->x_axis->is_category = LXW_TRUE;
 
     self->has_horiz_cat_axis = LXW_TRUE;
     self->has_horiz_val_axis = LXW_FALSE;
@@ -3300,6 +3305,7 @@ STATIC void
 _chart_initialize_column_chart(lxw_chart *self, uint8_t type)
 {
     self->has_horiz_val_axis = LXW_FALSE;
+    self->x_axis->is_category = LXW_TRUE;
 
     if (type == LXW_CHART_COLUMN_STACKED) {
         self->grouping = LXW_GROUPING_STACKED;
@@ -3338,6 +3344,7 @@ _chart_initialize_line_chart(lxw_chart *self)
 {
     _chart_set_default_marker_type(self, LXW_CHART_MARKER_NONE);
     self->grouping = LXW_GROUPING_STANDARD;
+    self->x_axis->is_category = LXW_TRUE;
 
     /* Initialize the function pointers for this chart type. */
     self->write_chart_type = _chart_write_line_chart;
@@ -3362,7 +3369,7 @@ STATIC void
 _chart_initialize_scatter_chart(lxw_chart *self)
 {
     self->has_horiz_val_axis = LXW_FALSE;
-    self->cross_between = LXW_CHART_AXIS_POSITION_ON_TICK;
+    self->default_cross_between = LXW_CHART_AXIS_POSITION_ON_TICK;
     self->is_scatter_chart = LXW_TRUE;
 
     if (self->type == LXW_CHART_SCATTER_STRAIGHT
@@ -3386,6 +3393,7 @@ _chart_initialize_radar_chart(lxw_chart *self, uint8_t type)
         _chart_set_default_marker_type(self, LXW_CHART_MARKER_NONE);
 
     self->x_axis->major_gridlines.visible = LXW_TRUE;
+    self->x_axis->is_category = LXW_TRUE;
 
     self->y_axis->major_tick_mark = LXW_TRUE;
 
@@ -3905,6 +3913,15 @@ chart_axis_off(lxw_chart_axis *axis)
     axis->hidden = LXW_TRUE;
 }
 
+/*
+ * Set the category axis position.
+ */
+void
+chart_axis_set_position(lxw_chart_axis *axis, uint8_t position)
+{
+    axis->position_axis = position;
+}
+
 /*
  * Set the minimum value for an axis.
  */

test/functional/src/test_chart_axis30.c

@@ -0,0 +1,44 @@
+/*****************************************************************************
+ * 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_axis30.xlsx");
+    lxw_worksheet *worksheet = workbook_add_worksheet(workbook, NULL);
+    lxw_chart     *chart     = workbook_add_chart(workbook, LXW_CHART_LINE);
+
+    /* For testing, copy the randomly generated axis ids in the target file. */
+    chart->axis_id_1 = 69200896;
+    chart->axis_id_2 = 69215360;
+
+    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_axis_set_position(chart->x_axis, LXW_CHART_AXIS_POSITION_ON_TICK);
+
+    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");
+
+    worksheet_insert_chart(worksheet, CELL("E9"), chart);
+
+    return workbook_close(workbook);
+}

test/functional/src/test_chart_axis31.c

@@ -0,0 +1,44 @@
+/*****************************************************************************
+ * 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_axis31.xlsx");
+    lxw_worksheet *worksheet = workbook_add_worksheet(workbook, NULL);
+    lxw_chart     *chart     = workbook_add_chart(workbook, LXW_CHART_BAR);
+
+    /* For testing, copy the randomly generated axis ids in the target file. */
+    chart->axis_id_1 = 90616960;
+    chart->axis_id_2 = 90618496;
+
+    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_axis_set_position(chart->y_axis, LXW_CHART_AXIS_POSITION_ON_TICK);
+
+    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");
+
+    worksheet_insert_chart(worksheet, CELL("E9"), chart);
+
+    return workbook_close(workbook);
+}

test/functional/src/test_chart_axis32.c

@@ -0,0 +1,44 @@
+/*****************************************************************************
+ * 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_axis32.xlsx");
+    lxw_worksheet *worksheet = workbook_add_worksheet(workbook, NULL);
+    lxw_chart     *chart     = workbook_add_chart(workbook, LXW_CHART_AREA);
+
+    /* For testing, copy the randomly generated axis ids in the target file. */
+    chart->axis_id_1 = 96171520;
+    chart->axis_id_2 = 96173056;
+
+    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_axis_set_position(chart->x_axis, LXW_CHART_AXIS_POSITION_BETWEEN);
+
+    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");
+
+    worksheet_insert_chart(worksheet, CELL("E9"), chart);
+
+    return workbook_close(workbook);
+}

test/functional/test_chart_axis.py

@@ -75,11 +75,18 @@ class TestCompareXLSXFiles(base_test_class.XLSXBaseTest):
     def test_chart_axis29(self):
         self.run_exe_test('test_chart_axis29')
 
+    def test_chart_axis30(self):
+        self.run_exe_test('test_chart_axis30')
+
+    def test_chart_axis31(self):
+        self.run_exe_test('test_chart_axis31')
+
+    def test_chart_axis32(self):
+        self.run_exe_test('test_chart_axis32')
 
     def test_chart_axis33(self):
         self.run_exe_test('test_chart_axis33')
 
-
     def test_chart_axis35(self):
         self.run_exe_test('test_chart_axis35')