Control horizontal and vertical space in grid.arrange with sliders in shiny app-CodePudding

I need to create a shiny app in which the user decides how many charts to display and in how many columns via sliders. To merge the graphs I used the function grid.arrange but it is not mandatory, the important thing is to have ggplot objects. And I need coord_fixed(). This is a small executable example:

library(shiny)
library(shinythemes)
library(readr)
library(ggplot2)
library(dplyr)
library(tidyr)
library(grid)
library(gridExtra)
library(ggforce) 
library(shinythemes)

ui <- fluidPage(
 
    navbarPage("MotorBrain", 
               
      tabPanel("Configurazione",
               sidebarLayout(
                   sidebarPanel( 
                      sliderInput("input1", "N. utenti",
                                    min = 1, max = 133,
                                    value = 3),
                       sliderInput("nCol1", "Ncols",
                                    min = 1, max = 32,
                                    value = 1),
                       actionButton("goButton1", "Visualizza")),
                       fluidRow()))),
      tabPanel("Visualizzazione", 
            fluidRow(
                   uiOutput("outputTest1"))
               
 ))




server <- function(input, output,session) {
    
 input1<-eventReactive(input$goButton1,{
        input$input1
    })
output$outputTest1 <- renderUI({ 
pl <- vector("list", length =  input1())
                        
for(t in 1: input1()) {

      p<-ggplot()  
         geom_point(x=runif(10000,0, 1),y=runif(500,0, 1)) 
         coord_fixed()
                             
 pl[[t]] <-p
                         
 }
                        
output$plot_test1<- renderPlot({
                    
 grid.arrange(grobs=pl,ncol=input$nCol1,top="")
                                
  })
                        
plotOutput(outputId = "plot_test1")
                        
 })                 

}

shinyApp(ui = ui, server = server)

I need to add two more sliders with which the user can decide how much horizontal and vertical white space to put between the various graphs in the grid. How can I do this?

CodePudding user response：

gridExtra added uncontrollable space between columns, so one solution is to use patchwork instead, where no extra space is added. Then we can use margin tricks to add space:

library(shiny)
library(shinythemes)
library(readr)
library(ggplot2)
library(dplyr)
library(tidyr)
library(grid)
library(ggforce) 
library(patchwork)

ui <- fluidPage(
    
    navbarPage("MotorBrain", 
               
               tabPanel("Configurazione",
                        sidebarLayout(
                            sidebarPanel( 
                                sliderInput("input1", "N. utenti",
                                            min = 1, max = 133,
                                            value = 3),
                                sliderInput("nCol1", "Ncols",
                                            min = 1, max = 32,
                                            value = 1),
                                sliderInput("h_space", "top bottom space (pt)",
                                            min = 1, max = 100,
                                            value = 1),
                                sliderInput("v_space", " left right space (pt)",
                                            min = 1, max = 100,
                                            value = 1),
                                actionButton("goButton1", "Visualizza")),
                            fluidRow()))),
    tabPanel("Visualizzazione", 
             fluidRow(
                 uiOutput("outputTest1"))
             
    ))




server <- function(input, output,session) {
    
    input1<-eventReactive(input$goButton1,{
        input$input1
    })
    output$outputTest1 <- renderUI({ 
        pl <- vector("list", length =  input1())
        for(t in 1: input1()) {
            p<-ggplot()  
                geom_point(x=runif(10000,0, 1),y=runif(500,0, 1)) 
                coord_fixed()  
                # the space is added to both sides, so we need to reduce by half
                theme(plot.margin = unit(c(
                    input$h_space/2,
                    input$v_space/2,
                    input$h_space/2,
                    input$v_space/2
                ), "pt"))
            
            pl[[t]] <-p
            
        }
        
        output$plot_test1<- renderPlot({
            Reduce(` `, pl)  
                plot_layout(ncol = input$nCol1)
        })
        
        plotOutput(outputId = "plot_test1")
        
    })                 
    
}

shinyApp(ui = ui, server = server)