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vxfw: add Padding widget
+149
+148
src/vxfw/Padding.zig
+148
src/vxfw/Padding.zig
···
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const std = @import("std");
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const vaxis = @import("../main.zig");
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const Allocator = std.mem.Allocator;
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const vxfw = @import("vxfw.zig");
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const Padding = @This();
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const PadValues = struct {
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left: u16 = 0,
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right: u16 = 0,
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top: u16 = 0,
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bottom: u16 = 0,
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};
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child: vxfw.Widget,
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padding: PadValues = .{},
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/// Vertical padding will be divided by 2 to approximate equal padding
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pub fn all(padding: u16) PadValues {
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return .{
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.left = padding,
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.right = padding,
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.top = padding / 2,
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.bottom = padding / 2,
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};
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}
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pub fn horizontal(padding: u16) PadValues {
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return .{
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.left = padding,
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.right = padding,
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};
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}
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pub fn vertical(padding: u16) PadValues {
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return .{
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.top = padding,
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.bottom = padding,
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};
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}
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pub fn widget(self: *const Padding) vxfw.Widget {
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return .{
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.userdata = @constCast(self),
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.eventHandler = typeErasedEventHandler,
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.drawFn = typeErasedDrawFn,
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};
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}
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fn typeErasedEventHandler(ptr: *anyopaque, ctx: *vxfw.EventContext, event: vxfw.Event) anyerror!void {
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const self: *const Padding = @ptrCast(@alignCast(ptr));
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return self.child.handleEvent(ctx, event);
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}
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fn typeErasedDrawFn(ptr: *anyopaque, ctx: vxfw.DrawContext) Allocator.Error!vxfw.Surface {
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const self: *const Padding = @ptrCast(@alignCast(ptr));
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return self.draw(ctx);
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}
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pub fn draw(self: *const Padding, ctx: vxfw.DrawContext) Allocator.Error!vxfw.Surface {
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const pad = self.padding;
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if (pad.left > 0 or pad.right > 0)
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std.debug.assert(ctx.max.width != null);
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if (pad.top > 0 or pad.bottom > 0)
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std.debug.assert(ctx.max.height != null);
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const inner_min: vxfw.Size = .{
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.width = ctx.min.width -| (pad.right + pad.left),
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.height = ctx.min.height -| (pad.top + pad.bottom),
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};
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const max_width: ?u16 = if (ctx.max.width) |max|
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max -| (pad.right + pad.left)
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else
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null;
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const max_height: ?u16 = if (ctx.max.height) |max|
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max -| (pad.top + pad.bottom)
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else
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null;
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const inner_max: vxfw.MaxSize = .{
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.width = max_width,
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.height = max_height,
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};
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const child_surface = try self.child.draw(ctx.withConstraints(inner_min, inner_max));
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const children = try ctx.arena.alloc(vxfw.SubSurface, 1);
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children[0] = .{
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.surface = child_surface,
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.z_index = 0,
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.origin = .{ .row = pad.top, .col = pad.left },
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};
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const size = .{
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.width = child_surface.size.width + (pad.right + pad.left),
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.height = child_surface.size.height + (pad.top + pad.bottom),
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};
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// Create the padding surface
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return .{
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.size = size,
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.widget = self.widget(),
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.buffer = &.{},
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.children = children,
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};
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}
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test Padding {
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const Text = @import("Text.zig");
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// Will be height=1, width=3
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const text: Text = .{ .text = "abc" };
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const padding: Padding = .{
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.child = text.widget(),
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.padding = horizontal(1),
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};
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var arena = std.heap.ArenaAllocator.init(std.testing.allocator);
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defer arena.deinit();
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const ucd = try vaxis.Unicode.init(arena.allocator());
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vxfw.DrawContext.init(&ucd, .unicode);
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// Center expands to the max size. It must therefore have non-null max width and max height.
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// These values are asserted in draw
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const ctx: vxfw.DrawContext = .{
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.arena = arena.allocator(),
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.min = .{},
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.max = .{ .width = 10, .height = 10 },
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};
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const pad_widget = padding.widget();
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const surface = try pad_widget.draw(ctx);
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// Padding does not produce any drawable cells
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try std.testing.expectEqual(0, surface.buffer.len);
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// Padding has 1 child
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try std.testing.expectEqual(1, surface.children.len);
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const child = surface.children[0];
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// Padding is the child size + padding
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try std.testing.expectEqual(child.surface.size.width + 2, surface.size.width);
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try std.testing.expectEqual(0, child.origin.row);
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try std.testing.expectEqual(1, child.origin.col);
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}
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test "refAllDecls" {
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std.testing.refAllDecls(@This());
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}
+1
src/vxfw/vxfw.zig
+1
src/vxfw/vxfw.zig
···
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pub const FlexColumn = @import("FlexColumn.zig");
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pub const FlexRow = @import("FlexRow.zig");
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pub const ListView = @import("ListView.zig");
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pub const Padding = @import("Padding.zig");
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pub const RichText = @import("RichText.zig");
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pub const Text = @import("Text.zig");
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pub const TextField = @import("TextField.zig");