From 68a3532728b55b73d8bcadb8ccfc1d9396346cd2 Mon Sep 17 00:00:00 2001
From: 3gg <3gg@shellblade.net>
Date: Sat, 13 Jul 2024 11:44:32 -0700
Subject: Basic table scrollbar rendering.
---
src/constants.h | 2 +-
src/input.c | 5 ++++-
src/layout.c | 6 ++++++
src/render.c | 22 ++++++++++++++++++++++
src/widget/widget.h | 10 ++++++----
5 files changed, 39 insertions(+), 6 deletions(-)
diff --git a/src/constants.h b/src/constants.h
index 457f461..0d93d14 100644
--- a/src/constants.h
+++ b/src/constants.h
@@ -4,4 +4,4 @@
#define MaxWidgetEvents 8
// Width of scroll bars in pixels.
-#define ScrollBarWidth 16
+#define ScrollBarWidth 32
diff --git a/src/input.c b/src/input.c
index c4b1be7..20551a6 100644
--- a/src/input.c
+++ b/src/input.c
@@ -6,6 +6,7 @@
#include <cassert.h>
+#define Min(a, b) ((a) < (b) ? (a) : (b))
#define Max(a, b) ((a) > (b) ? (a) : (b))
/// Return true if the rectangle contains the point.
@@ -85,7 +86,9 @@ static void ClickTable(uiTable* table, const uiMouseClickEvent* event) {
static void ScrollTable(uiTable* table, const uiMouseScrollEvent* event) {
assert(table);
assert(event);
- table->offset = Max(0, table->offset - event->scroll_offset);
+ table->offset =
+ Min(table->rows - table->num_visible_rows,
+ Max(0, table->offset - event->scroll_offset));
}
/// Process a scroll event.
diff --git a/src/layout.c b/src/layout.c
index 9d4b556..f83976f 100644
--- a/src/layout.c
+++ b/src/layout.c
@@ -13,6 +13,12 @@ static void ResizeTable(uiTable* table, int width, int height) {
return;
}
+ table->height = height;
+
+ // Compute the number of rows that are visible at once.
+ table->num_visible_rows = height / g_ui.font->header.glyph_height;
+ assert(table->num_visible_rows <= table->rows);
+
// Determine if there is vertical overflow. This determines whether we need to
// render a scroll bar, in which case room must be made for it.
table->flags.vertical_overflow =
diff --git a/src/render.c b/src/render.c
index 24490c0..b1fd3e8 100644
--- a/src/render.c
+++ b/src/render.c
@@ -186,6 +186,8 @@ static void RenderTable(const uiTable* table, RenderState* state) {
uiRect original_subsurface = {0};
uiPoint original_pen = {0};
+ int col_widths_sum = 0;
+
// Render header.
if (table->header) {
for (int col = 0; col < table->cols; ++col) {
@@ -201,6 +203,9 @@ static void RenderTable(const uiTable* table, RenderState* state) {
// Reset the original subsurface and pen for subsequent columns.
PopSubsurface(state, &original_subsurface, &original_pen);
+ // Keep track of the sum of column widths to later render the scroll bar.
+ col_widths_sum += table->widths[col];
+
// Next column.
state->pen.x += table->widths[col];
}
@@ -235,6 +240,23 @@ static void RenderTable(const uiTable* table, RenderState* state) {
state->pen.y += g_ui.font->header.glyph_height;
}
state->pen.y = y0;
+
+ // Render scrollbar.
+ if (table->flags.vertical_overflow) {
+ state->pen.x = col_widths_sum;
+
+ const int y_start = (int)((double)table->offset / (double)table->rows *
+ (double)table->height);
+
+ const int height = (int)((double)table->num_visible_rows /
+ (double)table->rows * (double)table->height);
+
+ FillRect(
+ &(uiRect){.y = y_start, .width = ScrollBarWidth, .height = height},
+ uiPink, state);
+
+ state->pen.x = x0;
+ }
}
/// Render a widget.
diff --git a/src/widget/widget.h b/src/widget/widget.h
index a2c96bc..c75bd65 100644
--- a/src/widget/widget.h
+++ b/src/widget/widget.h
@@ -54,10 +54,12 @@ typedef struct uiTable {
uiWidget widget;
int rows;
int cols;
- int* widths; // Width, in pixels, for each column.
- uiCell* header; // If non-null, row of 'cols' header cells.
- uiCell** cells; // Array of 'rows' rows, each of 'cols' cells.
- int offset; // Offset into the rows of the table. Units: rows.
+ int height; // Height in pixels.
+ int* widths; // Width, in pixels, for each column.
+ uiCell* header; // If non-null, row of 'cols' header cells.
+ uiCell** cells; // Array of 'rows' rows, each of 'cols' cells.
+ int offset; // Offset into the rows of the table. Units: rows.
+ int num_visible_rows; // The number of rows that are visible at once.
struct {
bool vertical_overflow : 1; // True if contents overflow vertically.
} flags;
--
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