pesos · MadhavJivrajani · Oct 10, 2020 · Oct 6, 2020 · Oct 6, 2020 · Oct 6, 2020
diff --git a/src/display/general/overallGraphs.go b/src/display/general/overallGraphs.go
@@ -25,13 +25,15 @@ import (
 	"time"
 
 	ui "github.com/gizak/termui/v3"
+	h "github.com/pesos/grofer/src/display/misc"
 	info "github.com/pesos/grofer/src/general"
 	"github.com/pesos/grofer/src/utils"
 )
 
 var isCPUSet = false
 
 var run = true
+var helpVisible = false
 
 // RenderCharts handles plotting graphs and charts for system stats in general.
 func RenderCharts(ctx context.Context,
@@ -46,6 +48,8 @@ func RenderCharts(ctx context.Context,
 	var on sync.Once
 	var totalBytesRecv float64
 	var totalBytesSent float64
+	var help *h.HelpMenu = h.NewHelpMenu()
+	h.SelectHelpMenu("main")
 
 	// Get number of cores in machine
 	numCores := runtime.NumCPU()
@@ -80,14 +84,22 @@ func RenderCharts(ctx context.Context,
 		if isCPUSet {
 			for i := 0; i < numCores; i++ {
 				myPage.CPUCharts[i].SetRect(0, i*height, w/2, (i+1)*height)
-				ui.Render(myPage.CPUCharts[i])
 			}
 		}
 
 		// Adjust Grid dimensions
 		myPage.Grid.SetRect(w/2, 0, w, h-heightOffset)
 
-		ui.Render(myPage.Grid)
+		help.Resize(w, h)
+
+		if helpVisible {
+			ui.Render(help)
+		} else {
+			ui.Render(myPage.Grid)
+			for i := 0; i < numCores; i++ {
+				ui.Render(myPage.CPUCharts[i])
+			}
+		}
 	}
 
 	updateUI() // Initialize empty UI
@@ -107,8 +119,30 @@ func RenderCharts(ctx context.Context,
 			case "<Resize>":
 				updateUI()
 
-			case "s": // s to stop
-				pause()
+			case "?": // s to stop
+				helpVisible = !helpVisible
+			}
+			if helpVisible {
+				switch e.ID {
+				case "?":
+					updateUI()
+				case "<Escape>":
+					helpVisible = false
+					updateUI()
+				case "j", "<Down>":
+					help.List.ScrollDown()
+					ui.Render(help)
+				case "k", "<Up>":
+					help.List.ScrollUp()
+					ui.Render(help)
+				}
+			} else {
+				switch e.ID {
+				case "?":
+					updateUI()
+				case "s": //s to pause
+					pause()
+				}
 			}
 
 		case data := <-dataChannel:
@@ -206,7 +240,12 @@ func RenderCharts(ctx context.Context,
 			}
 
 		case <-tick: // Update page with new values
-			updateUI()
+			if !helpVisible {
+				ui.Render(myPage.Grid)
+				for i := 0; i < numCores; i++ {
+					ui.Render(myPage.CPUCharts[i])
+				}
+			}
 		}
 	}
 }
@@ -216,6 +255,7 @@ func RenderCPUinfo(ctx context.Context,
 	refreshRate uint64) error {
 
 	var on sync.Once
+	var help *h.HelpMenu = h.NewHelpMenu()
 
 	if err := ui.Init(); err != nil {
 		return fmt.Errorf("failed to initialize termui: %v", err)
@@ -234,7 +274,12 @@ func RenderCPUinfo(ctx context.Context,
 		w, h := ui.TerminalDimensions()
 		ui.Clear()
 		myPage.Grid.SetRect(0, 0, w, h)
-		ui.Render(myPage.Grid)
+		help.Resize(w, h)
+		if helpVisible {
+			ui.Render(help)
+		} else {
+			ui.Render(myPage.Grid)
+		}
 	}
 
 	updateUI()
@@ -253,8 +298,30 @@ func RenderCPUinfo(ctx context.Context,
 			case "<Resize>":
 				updateUI()
 
-			case "s": // s to stop
-				pause()
+			case "?": // s to stop
+				helpVisible = !helpVisible
+			}
+			if helpVisible {
+				switch e.ID {
+				case "?":
+					updateUI()
+				case "<Escape>":
+					helpVisible = false
+					updateUI()
+				case "j", "<Down>":
+					help.List.ScrollDown()
+					ui.Render(help)
+				case "k", "<Up>":
+					help.List.ScrollUp()
+					ui.Render(help)
+				}
+			} else {
+				switch e.ID {
+				case "?":
+					updateUI()
+				case "s": //s to pause
+					pause()
+				}
 			}
 
 		case data := <-dataChannel: // Update chart values
@@ -279,7 +346,9 @@ func RenderCPUinfo(ctx context.Context,
 			}
 
 		case <-tick:
-			updateUI()
+			if !helpVisible {
+				ui.Render(myPage.Grid)
+			}
 		}
 	}
 }
diff --git a/src/display/misc/help.go b/src/display/misc/help.go
@@ -0,0 +1,83 @@
+/*
+Copyright © 2020 The PES Open Source Team pesos@pes.edu
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package help
+
+import (
+	ui "github.com/gizak/termui/v3"
+	"github.com/gizak/termui/v3/widgets"
+)
+
+var KEYBINDS []string
+
+type HelpMenu struct {
+	*widgets.List
+}
+
+func NewHelpMenu() *HelpMenu {
+	return &HelpMenu{
+		List: widgets.NewList(),
+	}
+}
+
+func (help *HelpMenu) Resize(termWidth, termHeight int) {
+	textWidth := 50
+	for _, line := range KEYBINDS {
+		if textWidth < len(line) {
+			textWidth = len(line) + 2
+		}
+	}
+	textHeight := len(KEYBINDS) + 3
+	x := (termWidth - textWidth) / 2
+	y := (termHeight - textHeight) / 2
+	if x < 0 {
+		x = 0
+		textWidth = termWidth
+	}
+	if y < 0 {
+		y = 0
+		textHeight = termHeight
+	}
+
+	help.List.SetRect(x, y, textWidth+x, textHeight+y)
+}
+
+func (help *HelpMenu) Draw(buf *ui.Buffer) {
+	help.List.Title = " Keybindings "
+
+	help.List.Rows = KEYBINDS
+	help.List.TextStyle = ui.NewStyle(ui.ColorYellow)
+	help.List.WrapText = false
+	help.List.Draw(buf)
+}
+
+func SelectHelpMenu(page string) {
+	switch page {
+	case "proc":
+		KEYBINDS = PROC_KEYBINDS
+	case "proc_pid":
+		KEYBINDS = PROC_PID_KEYBINDS
+	case "main":
+		KEYBINDS = MAIN_KEYBINDS
+	}
+}
+
+func maxInt(a int, b int) int {
+	if a > b {
+		return a
+	}
+	return b
+}
diff --git a/src/display/misc/keybinds.go b/src/display/misc/keybinds.go
@@ -0,0 +1,42 @@
+/*
+Copyright © 2020 The PES Open Source Team pesos@pes.edu
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package help
+
+var PROC_KEYBINDS = []string{
+	"Quit: q or <C-c>",
+	"",
+	"Process navigation:",
+	"  - k and <Up>: up",
+	"  - j and <Down>: down",
+	"  - <C-u>: half page up",
+	"  - <C-d>: half page down",
+	"  - <C-b>: full page up",
+	"  - <C-f>: full page down",
+	"  - gg and <Home>: jump to top",
+	"  - G and <End>: jump to bottom",
+	"",
+	"Process actions:",
+	"  - K and <F9>: Kill process",
+}
+
+var MAIN_KEYBINDS = []string{
+	"Quit: q or <C-c>",
+}
+
+var PROC_PID_KEYBINDS = []string{
+	"Quit: q or <C-c>",
+}