LAMW Bug: UpdateLayout After Rotate
lazarus / 43-Android

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Handoko · 2019-02-12 18:31

When learning how to use jView, I found something not working
correctly. I could be wrong but I believe it is a bug.

How to reproduce the bug?

1. Run the code below (you can download and use the apk on the next
post)
2. Press the button several times, to switch between different layout
parameters
3. A small rectangle and triangle will be moving inside the jView1
4. The big green rectangle represents the border of jView1
5. Rotate your mobile phone

6. Bug:
If the jView1.LayoutParam = lpMatchParent and the phone orientation is
Landscape then
the value of jView1.Width and jView1.Height are incorrect (swapped).

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i {Hint: save
all files to location:
/home/handoko/Desktop/JCanvasPolygon/LamwGUIProject1/jni }unit
unit1; {$mode delphi} interface uses  Classes, SysUtils,
AndroidWidget, Laz_And_Controls;  type   TPolygon = array of TPoint;  
{ TAndroidModule1 }   TAndroidModule1 = class(jForm)    jButton1:
jButton;    jCanvas1: jCanvas;    jTextView1: jTextView;    jTimer1:
jTimer;    jView1: jView;    procedure AndroidModule1Destroy(Sender:
TObject);    procedure AndroidModule1JNIPrompt(Sender: TObject);   
procedure AndroidModule1Rotate(Sender: TObject; rotate:
TScreenStyle);    procedure jButton1Click(Sender: TObject);   
procedure jTimer1Timer(Sender: TObject);    procedure
jView1Draw(Sender: TObject);  private    FBorderS: Integer;   
FSquareX: Integer;    FSquareY: Integer;    FSquareS: Integer;   
FSquareVeloX: Integer;    FSquareVeloY: Integer;    FTriangleX:
Integer;    FTriangleY: Integer;    FTriangleVeloX: Integer;   
FTriangleVeloY: Integer;    procedure DrawPoly(BorderColor:
TARGBColorBridge; BorderWidth: Integer;      Points: TPolygon);   
procedure ShowInfo;  end; var  AndroidModule1:
TAndroidModule1; implementation {$R *.lfm} { TAndroidModule1
} procedure TAndroidModule1.jView1Draw(Sender: TObject);var  Polygon:
TPolygon;begin   // Draw Border  Polygon := TPolygon.Create(   
Point(0, 0),    Point(jView1.Width, 0),    Point(jView1.Width,
jView1.Height),    Point(0, jView1.Height));  DrawPoly(colbrGreen,
FBorderS, Polygon);   // Draw Square  Polygon := TPolygon.Create(   
Point(FSquareX-FSquareS, FSquareY-FSquareS),   
Point(FSquareX+FSquareS, FSquareY-FSquareS),   
Point(FSquareX+FSquareS, FSquareY+FSquareS),    Point(FSquareX-
FSquareS, FSquareY+FSquareS));  DrawPoly(colbrCyan, 3, Polygon);   //
Draw Triangle  Polygon := TPolygon.Create(    Point(FTriangleX,    
FTriangleY-80),    Point(FTriangleX+100, FTriangleY+80),   
Point(FTriangleX-100, FTriangleY+80));  DrawPoly(colbrRed, 3,
Polygon); end; procedure TAndroidModule1.jButton1Click(Sender:
TObject);const  Layout: Integer = 0;begin  Inc(Layout);  if Layout > 3
then Layout := 1;  case Layout of    1: begin     
jView1.LayoutParamHeight := lpMatchParent;     
jView1.LayoutParamWidth  := lpMatchParent;      jButton1.Text        
  := 'lpMatchParent';    end;    2: begin     
jView1.LayoutParamHeight := lpFourFifthOfParent;     
jView1.LayoutParamWidth  := lpFourFifthOfParent;      jButton1.Text  
        := 'lpFourFifthOfParent';    end;    3: begin     
jView1.LayoutParamHeight := lp99PercentOfParent;     
jView1.LayoutParamWidth  := lp99PercentOfParent;      jButton1.Text  
        := 'lp99PercentOfParent';    end;  end;  jView1.UpdateLayout; 
ShowInfo;end; procedure TAndroidModule1.jTimer1Timer(Sender:
TObject);begin   // Animate Border  Inc(FBorderS);  if FBorderS > 50
then FBorderS := 1;   // Animate Square  Inc(FSquareS);  if FSquareS >
200 then            FSquareS := 50;  if FSquareX <= 0  then          
 FSquareVeloX := abs(FSquareVeloX);  if FSquareX >= jView1.Width then
 FSquareVeloX := -(abs(FSquareVeloX));  if FSquareY <= 0  then       
   FSquareVeloY := abs(FSquareVeloY);  if FSquareY >= jView1.Height
then FSquareVeloY := -(abs(FSquareVeloY));  Inc(FSquareX,
FSquareVeloX);  Inc(FSquareY, FSquareVeloY);   // Animate Triangle  if
FTriangleX <= 0  then            FTriangleVeloX := Random(8)  +1;  if
FTriangleX >= jView1.Width  then FTriangleVeloX := -Random(8) -1;  if
FTriangleY <= 0  then            FTriangleVeloY := Random(8)  +1;  if
FTriangleY >= jView1.Height then FTriangleVeloY := -Random(8) -1; 
Inc(FTriangleX, FTriangleVeloX);  Inc(FTriangleY, FTriangleVeloY);  
jView1.Refresh; end; procedure
TAndroidModule1.AndroidModule1Destroy(Sender: TObject);begin 
jTimer1.Enabled := False;end; procedure
TAndroidModule1.AndroidModule1JNIPrompt(Sender: TObject);begin   //
Initial Border  FBorderS := 1;   // Initialize Square  FSquareX     :=
(jView1.Width div 2) -100;  FSquareY     := jView1.Height div 2; 
FSquareS     := 50;  FSquareVeloX := Random(8) +1;  FSquareVeloY :=
Random(8) +1;   // Initialize Triangle  FTriangleX     :=
(jView1.Width div 2) +100;  FTriangleY     := jView1.Height div 2; 
FTriangleVeloX := Random(8) +1;  FTriangleVeloY := Random(8) +1;  
jTimer1.Enabled := True;  ShowInfo; end; procedure
TAndroidModule1.AndroidModule1Rotate(Sender: TObject;  rotate:
TScreenStyle);begin  jView1.UpdateLayout;end; procedure
TAndroidModule1.DrawPoly(BorderColor: TARGBColorBridge;  BorderWidth:
Integer; Points: TPolygon);var  i: Integer;begin 
jView1.Canvas.PaintColor       := BorderColor; 
jView1.Canvas.PaintStrokeWidth := BorderWidth;  for i := Low(Points)
to High(Points)-1 do    jCanvas1.drawLine(Points[i].x, Points[i].y,
Points[i+1].x, Points[i+1].y);  i := High(Points); 
jView1.Canvas.drawLine(Points[i].X, Points[i].Y, Points[0].X,
Points[0].Y);end; procedure TAndroidModule1.ShowInfo;begin 
jTextView1.Text := jView1.Width.ToString + ' x ' +
jView1.Height.ToString;end; end.

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Handoko · 2019-02-12 18:34

Below is the apk file.

Note:
Tested on Redmi 4X Android 7.1.2 LAMW 0.7 Lazarus 1.8.4.
I first notice this issue because the moving objects move to the
outside the visible screen area. To make it clearly, I have added the
green border. So you can ignore the moving objects.

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loaded · 2019-02-12 18:59

Handoko, I don't think it's a bug.
There's something we don't know. I found the solution in the following
way.

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i {Hint: save
all files to location:
C:\Users\loaded\Desktop\silan\AppLAMWProject2\jni }unit unit1; {$mode
delphi} interface uses  Classes, SysUtils, AndroidWidget,
Laz_And_Controls;  type   { TAndroidModule1 }   TAndroidModule1 =
class(jForm)    jCanvas1: jCanvas;    jView1: jView;    procedure
AndroidModule1Rotate(Sender: TObject; rotate: TScreenStyle);   
procedure jView1Draw(Sender: TObject);   private    {private
declarations}  public    {public declarations}  end; var 
AndroidModule1: TAndroidModule1; 
J_Rotate:Boolean=false;implementation  {$R *.lfm}   { TAndroidModule1
}procedure TAndroidModule1.jView1Draw(Sender: TObject);begin  if
J_Rotate then  begin 
showmessage(inttostr(jView1.Width)+'x'+inttostr(jView1.Height)); 
J_Rotate:=false;  end;end;   procedure
TAndroidModule1.AndroidModule1Rotate(Sender: TObject;  rotate:
TScreenStyle);begin  Self.UpdateLayout;  J_Rotate:=true; 
jView1.Refresh;end; end.