big buffer/buffer_view rework

A buffer is only the text and the corresponding operation. A buffer view
holds information about scroll, dot and mark positions. One way to think
about it is that a buffer is stateless whereas a buffer view is stateful.

1 files changed, 81 insertions, 0 deletions

diff --git a/src/dged/location.h b/src/dged/location.h
new file mode 100644
index 0000000..d11dd94
--- /dev/null
+++ b/src/dged/location.h
@@ -0,0 +1,81 @@
+#ifndef _LOCATION_H
+#define _LOCATION_H
+
+#include <stdbool.h>
+#include <stdint.h>
+
+/**
+ * A location inside text.
+ */
+struct location {
+  /** The line in the text (0..) */
+  uint32_t line;
+
+  /** The column in the text (0..) */
+  uint32_t col;
+};
+
+/**
+ * Is the location between two other locations.
+ *
+ * @param [in] location The location to test.
+ * @param [in] l1 The first location.
+ * @param [in] l2 The other location.
+ * @returns True if @ref location is between @ref l1 and @ref l2.
+ */
+bool location_is_between(struct location location, struct location l1,
+                         struct location l2);
+
+/**
+ * Compare two locations.
+ *
+ * @param [in] l1 The first location.
+ * @param [in] l2 The second location.
+ *
+ * @returns -1 if @ref l1 is before @ref l2, 0 if @ref l1 is equal to @ref l2
+ *          and +1 if @ref l1 is after @ref l2.
+ */
+int location_compare(struct location l1, struct location l2);
+
+/**
+ * A region (area) in text.
+ */
+struct region {
+  /** The top left corner of the region. */
+  struct location begin;
+
+  /** The bottom right corner of the region. */
+  struct location end;
+};
+
+/**
+ * Create a new region.
+ *
+ * Note that if begin is after end, their order will be reversed.
+ *
+ * @param [in] begin The point in the text where this region begins.
+ * @param [in] end The point in the text where this region ends.
+ * @returns a new region.
+ */
+struct region region_new(struct location begin, struct location end);
+
+/**
+ * Is this region covering anything?
+ *
+ * @param [in] region The region to check.
+ * @returns True if the region has a size > 0.
+ */
+bool region_has_size(struct region region);
+
+/**
+ * Is the location inside the region?
+ *
+ * @param [in] region The region to test.
+ * @param [in] location The location to test.
+ * @returns True if @ref location is inside @ref region.
+ */
+bool region_is_inside(struct region region, struct location location);
+
+bool region_is_inside_rect(struct region region, struct location location);
+
+#endif