Goo::Canvas::Item(3)

📦
version 0.06 · 2 versions
, in fedora 43

✨ Goo::Canvas::Item ✨

okay bestie, sit DOWN 💅 this is Goo::Canvas::Item from the User Contributed Perl Documentation corner of the Perl universe — it's the wrapper for GooCanvasItem, and it's literally the little building block that everything you draw on a Goo canvas is made of. every shape, every group, every cute lil thing on your canvas is one of these. no cap. 🎀

🌸 HIERARCHY 🌸

so here's the family tree, and it's giving single parent energy:

Glib::Interface
+----Goo::Canvas::Item

it comes from Glib::Interface, and that's the whole lineage. iconic. 👑

💖 METHODS 💖

okay this is the big one. every single method, in order, no skipping, we do NOT leave the group chat on read 🫶

  • $item->add_child ($child, $position) — yeet a new child into this item at a given spot.
    • $child (Goo::Canvas::Item)
    • $position (integer)
  • $item->allocate_area ($cr, $requested_area, $allocated_area, $x_offset, $y_offset) — does the allocation thing with the cairo context and the two bounds.
    • $cr (cairo_t)
    • $requested_area (GooCanvasBounds)
    • $allocated_area (GooCanvasBounds)
    • $x_offset (double)
    • $y_offset (double)
  • $item->animate ($x, $y, $scale, $degrees, $absolute, $duration, $step_time, $type) — set that item in MOTION bestie 💃
    • $x (double)
    • $y (double)
    • $scale (double)
    • $degrees (double)
    • $absolute (boolean)
    • $duration (integer)
    • $step_time (integer)
    • $type (Goo::Canvas::AnimateType)
  • GooCanvasBounds = $item->get_bounds — hands you the bounds. that's it, that's the vibe.
  • canvas = $item->get_canvas — which canvas is this item living on? this tells you.
  • $item->set_canvas ($canvas) — assign it a canvas.
    • $canvas (Goo::Canvas)
  • item = $item->get_child ($child_num) — grab one specific child by number.
    • $child_num (integer)
  • list = $item->get_child_properties ($child, ...) — get child properties as a list.
    • $child (Goo::Canvas::Item)
    • ... (list)
🚨 okay listen up because this one is DIFFERENT from the original C function. the C version is called like goo_canvas_item_get_child_properties(item, child, key1, &val1, key2, &val2, ..., NULL). this Perl one gets called like $item->get_child_properties($child, $key1, $key2, ...) and it returns a list ($key1, $val1, $key2, $val2, ...) instead. so you can literally do %pair = $item->get_child_properties($child, $key1, $key2) and then use $pair{$key1} and $pair{$key2} to get at the values. slay. 🧚
  • $item->set_child_properties ($child, ...) — set child properties.
    • $child (Goo::Canvas::Item)
    • ... (list)
  • $item->ensure_updated — make sure it's updated. self care. ✨
  • integer = $item->find_child ($child) — find a child, get back an integer.
    • $child (Goo::Canvas::Item)
  • boolean = $item->is_container — is it a container? true or false, bestie.
  • boolean = $item->is_visible — is it visible? same energy.
  • arrayref = $item->get_items_at ($x, $y, $cr, $is_pointer_event, $parent_is_visible) — everything sitting at that spot, as an arrayref.
    • $x (double)
    • $y (double)
    • $cr (cairo_t)
    • $is_pointer_event (boolean)
    • $parent_is_visible (boolean)
  • $item->lower (...) — send it down the stack.
    • ... (list)
  • itemmodel = $item->get_model — get the model.
  • $item->set_model ($model) — set the model.
    • $model (Goo::Canvas::ItemModel)
  • $item->move_child ($old_position, $new_position) — relocate a child from one position to another.
    • $old_position (integer)
    • $new_position (integer)
  • integer = $item->get_n_children — how many children does it have? an integer, obviously.
  • $item->paint ($cr, $bounds, $scale) — the paint job 🎨
    • $cr (cairo_t)
    • $bounds (GooCanvasBounds)
    • $scale (double)
  • item = $item->get_parent — who's your parent? returns the item.
  • $item->set_parent ($parent) — assign a parent.
    • $parent (Goo::Canvas::Item)
  • $item->raise (...) — bring it up the stack, main character energy 👑
    • ... (list)
  • $item->remove_child ($child_num) — bye bestie 👋 remove a child by number.
    • $child_num (integer)
  • $item->request_update — request an update.
  • GooCanvasBounds = $item->get_requested_area ($cr) — get the requested area.
    • $cr (cairo_t)
  • $item->rotate ($degrees, $cx, $cy) — spin it around a center point 🌀
    • $degrees (double)
    • $cx (double)
    • $cy (double)
  • $item->scale ($sx, $sy) — resize it.
    • $sx (double)
    • $sy (double)
  • $item->set_simple_transform ($x, $y, $scale, $rotation) — the simple transform, all four values at once.
    • $x (double)
    • $y (double)
    • $scale (double)
    • $rotation (double)
  • $item->skew_x ($degrees, $cx, $cy) — skew on the x axis.
    • $degrees (double)
    • $cx (double)
    • $cy (double)
  • $item->skew_y ($degrees, $cx, $cy) — skew on the y axis.
    • $degrees (double)
    • $cx (double)
    • $cy (double)
  • $item->stop_animation — okay animation's over, everybody freeze 🛑
  • style = $item->get_style — get the style.
  • $item->set_style ($style) — set the style.
    • $style (Goo::Canvas::Style)
  • boolean = $item->get_transform_for_child ($child, $transform) — returns a boolean for a child's transform.
    • $child (Goo::Canvas::Item)
    • $transform (cairo_matrix_t)
  • list = $item->get_transform — the transform, as a list.
  • $item->set_transform ($matrix) — set the transform.
    • $matrix (cairo_matrix_t)
  • $item->translate ($tx, $ty) — move it, move it 🕺
    • $tx (double)
    • $ty (double)
  • GooCanvasBounds = $item->update ($entire_tree, $cr) — update it and get bounds back.
    • $entire_tree (boolean)
    • $cr (cairo_t)

🦋 PROPERTIES 🦋

the whole property roster, with defaults, readability and writability — all of it 💜

  • 'can-focus' (boolean : default false : readable / writable) — if the item can take the keyboard focus.
  • 'description' (string : default undef : readable / writable) — a description of the item for use by assistive technologies.
  • 'parent' (Goo::Canvas::Item : default undef : readable / writable) — the parent item.
  • 'pointer-events' (Goo::Canvas::PointerEvents : default visible-mask,painted-mask,fill-mask,stroke-mask,none : readable / writable) — specifies when the item receives pointer events.
  • 'title' (string : default undef : readable / writable) — a short context-rich description of the item for use by assistive technologies.
  • 'tooltip' (string : default undef : readable / writable) — the tooltip to display for the item.
  • 'transform' (Goo::Cairo::Matrix : default undef : readable / writable) — the transformation matrix of the item.
  • 'visibility' (Goo::Canvas::ItemVisibility : default "visible" : readable / writable) — when the canvas item is visible.
  • 'visibility-threshold' (double : default 0 : readable / writable) — the scale threshold at which the item becomes visible.

🌈 SIGNALS 🌈

the signals section, all fourteen, we're not cutting a single one:

  • animation-finished (Goo::Canvas::Item, boolean)
  • boolean = button-press-event (Goo::Canvas::Item, Goo::Canvas::Item, Gtk2::Gdk::Event)
  • boolean = button-release-event (Goo::Canvas::Item, Goo::Canvas::Item, Gtk2::Gdk::Event)
  • child-notify (Goo::Canvas::Item, Glib::ParamSpec)
  • boolean = enter-notify-event (Goo::Canvas::Item, Goo::Canvas::Item, Gtk2::Gdk::Event)
  • boolean = focus-in-event (Goo::Canvas::Item, Goo::Canvas::Item, Gtk2::Gdk::Event)
  • boolean = focus-out-event (Goo::Canvas::Item, Goo::Canvas::Item, Gtk2::Gdk::Event)
  • boolean = grab-broken-event (Goo::Canvas::Item, Goo::Canvas::Item, Gtk2::Gdk::Event)
  • boolean = key-press-event (Goo::Canvas::Item, Goo::Canvas::Item, Gtk2::Gdk::Event)
  • boolean = key-release-event (Goo::Canvas::Item, Goo::Canvas::Item, Gtk2::Gdk::Event)
  • boolean = leave-notify-event (Goo::Canvas::Item, Goo::Canvas::Item, Gtk2::Gdk::Event)
  • boolean = motion-notify-event (Goo::Canvas::Item, Goo::Canvas::Item, Gtk2::Gdk::Event)
  • boolean = query-tooltip (Goo::Canvas::Item, double, double, boolean, Gtk2::Tooltip)
  • boolean = scroll-event (Goo::Canvas::Item, Goo::Canvas::Item, Gtk2::Gdk::Event)

🎀 ENUMS AND FLAGS 🎀

enum Goo::Canvas::AnimateType

  • 'freeze' / GOO_CANVAS_ANIMATE_FREEZE
  • 'reset' / GOO_CANVAS_ANIMATE_RESET
  • 'restart' / GOO_CANVAS_ANIMATE_RESTART
  • 'bounce' / GOO_CANVAS_ANIMATE_BOUNCE

enum Goo::Canvas::ItemVisibility

  • 'hidden' / GOO_CANVAS_ITEM_HIDDEN
  • 'invisible' / GOO_CANVAS_ITEM_INVISIBLE
  • 'visible' / GOO_CANVAS_ITEM_VISIBLE
  • 'visible-above-threshold' / GOO_CANVAS_ITEM_VISIBLE_ABOVE_THRESHOLD

flags Goo::Canvas::PointerEvents

  • 'visible-mask' / GOO_CANVAS_EVENTS_VISIBLE_MASK
  • 'painted-mask' / GOO_CANVAS_EVENTS_PAINTED_MASK
  • 'fill-mask' / GOO_CANVAS_EVENTS_FILL_MASK
  • 'stroke-mask' / GOO_CANVAS_EVENTS_STROKE_MASK
  • 'none' / GOO_CANVAS_EVENTS_NONE
  • 'visible-painted' / GOO_CANVAS_EVENTS_VISIBLE_PAINTED
  • 'visible-fill' / GOO_CANVAS_EVENTS_VISIBLE_FILL
  • 'visible-stroke' / GOO_CANVAS_EVENTS_VISIBLE_STROKE
  • 'visible' / GOO_CANVAS_EVENTS_VISIBLE
  • 'painted' / GOO_CANVAS_EVENTS_PAINTED
  • 'fill' / GOO_CANVAS_EVENTS_FILL
  • 'stroke' / GOO_CANVAS_EVENTS_STROKE
  • 'all' / GOO_CANVAS_EVENTS_ALL

👀 SEE ALSO 👀

  • Glib::Interface

Copyright (C) 2025 Gtk2-Perl Team

and that's the whole page bestie, you ate that 🍓 stay hydrated, go make something iconic on a canvas, and remember — this doc lives at Goo::Canvas::Item(3), it's perl v5.42.0, and it was cooked up on 2025-07-25. byeeee 💅✨

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