## ----setup, include = FALSE---------------------------------------------------
knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>",
  fig.width = 7,
  fig.height = 5
)
library(ggguides)
library(ggplot2)

# Theme with transparent backgrounds for pkgdown light/dark mode
theme_set(
  theme_grey() +
    theme(
      plot.background = element_rect(fill = "transparent", color = NA),
      panel.background = element_rect(fill = "transparent", color = NA),
      legend.background = element_rect(fill = "transparent", color = NA),
      legend.key = element_rect(fill = "transparent", color = NA),
      legend.box.background = element_rect(fill = "transparent", color = NA)
    )
)

## ----problem, fig.height=4----------------------------------------------------
library(patchwork)

p1 <- ggplot(mtcars, aes(mpg, wt, color = factor(cyl))) +
  geom_point() + labs(title = "Plot 1", color = "Cylinders")
p2 <- ggplot(mtcars, aes(mpg, hp, color = factor(cyl))) +
  geom_point() + labs(title = "Plot 2", color = "Cylinders")

# Default patchwork: duplicate legends
p1 | p2

## ----collect-basic, fig.height=4----------------------------------------------
collect_legends(p1 | p2)

## ----collect-bottom, fig.height=5---------------------------------------------
collect_legends(p1 | p2, position = "bottom")

## ----collect-left, fig.height=4-----------------------------------------------
collect_legends(p1 | p2, position = "left")

## ----stacked-default, fig.height=7--------------------------------------------
# Create plots with different heights using plot_layout
p3 <- ggplot(mtcars, aes(mpg, disp, color = factor(cyl))) +
  geom_point() + labs(title = "Plot 3", color = "Cylinders")

# Stack with different heights: 1, 1/2, 1/4
stacked <- (p1 / p2 / p3) + plot_layout(heights = c(4, 2, 1))
collect_legends(stacked, position = "right")

## ----stacked-span, fig.height=7-----------------------------------------------
gt <- collect_legends(stacked, position = "right", span = TRUE)
grid::grid.draw(gt)

## ----span-row1, fig.height=7--------------------------------------------------
# Legend attached to row 1 only (the tallest plot)
gt <- collect_legends(stacked, position = "right", span = 1)
grid::grid.draw(gt)

## ----span-row12, fig.height=7-------------------------------------------------
# Legend attached to rows 1 and 2
gt <- collect_legends(stacked, position = "right", span = 1:2)
grid::grid.draw(gt)

## ----collect-axes, fig.height=5-----------------------------------------------
# Plots stacked vertically - x-axis is duplicated
p_top <- ggplot(mtcars, aes(mpg, wt)) +
  geom_point() + labs(y = "Weight")

p_bottom <- ggplot(mtcars, aes(mpg, disp)) +
  geom_point() + labs(y = "Displacement")

# Without axis collection (both have x-axis)
p_top / p_bottom

## ----collect-axes-fixed, fig.height=5-----------------------------------------
# With axis collection (removes redundant x-axis from top)
collect_axes(p_top / p_bottom)

## ----combined, fig.height=5---------------------------------------------------
p1_styled <- p1 + legend_style(size = 11, title_face = "bold")
p2_styled <- p2 + legend_style(size = 11, title_face = "bold")

collect_legends(p1_styled | p2_styled, position = "right")

## ----complex, fig.height=6----------------------------------------------------
p4 <- ggplot(mtcars, aes(qsec, wt, color = factor(cyl))) +
  geom_point() + labs(title = "Plot 4", color = "Cylinders")

# 2x2 grid
layout <- (p1 | p2) / (p3 | p4)
collect_legends(layout, position = "right")

## ----cowplot-setup, include=FALSE---------------------------------------------
# Fresh plots for cowplot examples (not modified by patchwork)
cp1 <- ggplot(mtcars, aes(mpg, wt, color = factor(cyl))) +
  geom_point() + labs(title = "Plot 1", color = "Cylinders")
cp2 <- ggplot(mtcars, aes(mpg, hp, color = factor(cyl))) +
  geom_point() + labs(title = "Plot 2", color = "Cylinders")
cp3 <- ggplot(mtcars, aes(mpg, disp, color = factor(cyl))) +
  geom_point() + labs(title = "Plot 3", color = "Cylinders")
cp4 <- ggplot(mtcars, aes(qsec, wt, color = factor(cyl))) +
  geom_point() + labs(title = "Plot 4", color = "Cylinders")

## ----get-legend---------------------------------------------------------------
# Extract legend from a plot
leg <- get_legend(cp1)

# Use with cowplot::plot_grid() or grid::grid.draw()
grid::grid.newpage()
grid::grid.draw(leg)

## ----shared-legend-side, fig.height=4-----------------------------------------
# Side-by-side with shared legend on right
gt <- shared_legend(cp1, cp2, ncol = 2, position = "right")
grid::grid.newpage()
grid::grid.draw(gt)

## ----shared-legend-stacked, fig.height=6--------------------------------------
# Stacked with legend at bottom
gt <- shared_legend(cp1, cp2, cp3, ncol = 1, position = "bottom")
grid::grid.newpage()
grid::grid.draw(gt)

## ----shared-legend-grid, fig.height=5-----------------------------------------
# 2x2 grid
gt <- shared_legend(cp1, cp2, cp3, cp4, ncol = 2, nrow = 2, position = "right")
grid::grid.newpage()
grid::grid.draw(gt)