asked on

HTML Page Preview or (even better) thumbnail viewer of a folder with html files

Hi,

Please help me with this:

I need either to make a preview of a local html page. I`ve tried something with the TWebBrowser but the prob is that I can`t stretch the page there. That would have been perfect! Or even better I would like thumbnail viewer of a folder with html pages. I`m sure the first one is simpler. It would be best if it could happen without any components or with free components.

This is urgent. Thanks!

Cristian

Russell Libby

Cristian,

Have you already taken a look at, or tried the code from this PAQ?

https://www.experts-exchange.com/questions/21608891/Web-Page-Snapshots-good-solution-but-help-needed.html

It uses the browser control to create snapshots (also scaled image snapshots) from an html page. Perhaps this is close to what you are looking for?

Russell

CristianIgnat

ASKER

Yep, thanks a lot.
Can you tell me also how can I make a webbrowser not visible ? cos I put false there but it still appears on the form. Thanks.

ASKER CERTIFIED SOLUTION

Russell Libby

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CristianIgnat

ASKER

Hi rllibby,

you`re solution looks simpler! the prob is it doesn`t find the CreateScaledImage. in what unit is that ?

Thanks

Russell Libby

Its the second version of WebUtils from the link; I am posting it here so there is no confusion:

unit WebUtils;
////////////////////////////////////////////////////////////////////////////////
//
// Unit : WebUtils
// Date : 10.27.2005 (updated 10.28.2005)
// Description : Utility functions based on the TWebBrowser object
//
//
// function GetDocumentSize(Browser: TWebBrowser): TPoint;
//
// Returns the document's body size as a TPoint, where X = width and Y = height
//
// function GetBrowserElement(Browser: TWebBrowser; out Element: IHTMLElement2): HResult;
//
// Returns the actual element required to perform the rendering to a canvas handle.
// For most pages, this will be the body element. But for some, eg:
//
// https://www.experts-exchange.com
// http://www.msn.com
//
// the parent element will need to be used. The element to use is based on
// getting the parent and checking it for a clientwidth/height of zero. If zero,
// then the body element can be used. If not zero, then the parent must be used.
//
// function CreateThumbnailImage(Browser: TWebBrowser; OutputSize: TPoint): TBitmap;
//
// Returns a bitmap object of the document page where the width and height is
// determined by the point (x = width, y=height) passed in OutputSize.
//
// function CreateScaledImage(Browser: TWebBrowser; Scale: Double): TBitmap;
//
// Returns a scaled bitmap object of the document page. A scaling of 1.0 will
// return the page at its actual size. To return a 1/10 scaled image of the
// document for example, 0.1 would be passed to Scale.
//
////////////////////////////////////////////////////////////////////////////////
interface

////////////////////////////////////////////////////////////////////////////////
// Include units
////////////////////////////////////////////////////////////////////////////////
uses
Windows, SysUtils, Classes, Graphics, ShdocVW, ActiveX, MSHTML;

////////////////////////////////////////////////////////////////////////////////
// Constants
////////////////////////////////////////////////////////////////////////////////
const
IID_IHTMLElementRender: TGUID = '{3050F669-98B5-11CF-BB82-00AA00BDCE0B}';

////////////////////////////////////////////////////////////////////////////////
// Interfaces
////////////////////////////////////////////////////////////////////////////////
type
IHTMLElementRender = interface(IUnknown)
['{3050F669-98B5-11CF-BB82-00AA00BDCE0B}']
function DrawToDC(_hDC: HDC): HResult; stdcall;
function SetDocumentPrinter(bstrPrinterName: WideString; _hDC: HDC): HResult; stdcall;
end;

////////////////////////////////////////////////////////////////////////////////
// Utility functions
////////////////////////////////////////////////////////////////////////////////
function GetDocumentSize(Browser: TWebBrowser): TPoint;
function GetBrowserElement(Browser: TWebBrowser; out Element: IHTMLElement2): HResult;
function CreateThumbnailImage(Browser: TWebBrowser; OutputSize: TPoint): TBitmap;
function CreateScaledImage(Browser: TWebBrowser; Scale: Double): TBitmap;

implementation

function GetBrowserElement(Browser: TWebBrowser; out Element: IHTMLElement2): HResult;
var pDoc: IHTMLDocument2;
pElemParent: IHTMLElement;
pElement: IHTMLElement;
pElement2: IHTMLElement2;
begin

// Check browser document
if Assigned(Browser.Document) then
begin
// QI for document 2 interface
result:=Browser.Document.QueryInterface(IHTMLDocument2, pDoc);
// Check result
if Succeeded(result) then
begin
// Resource protection
try
// Check document body
if Assigned(pDoc.Body) then
begin
// QI for body element
result:=pDoc.Body.QueryInterface(IHTMLElement, pElement);
// Check result
if Succeeded(result) then
begin
// Resource protection
try
// Get parent element
pElemParent:=pElement.parentElement;
// Check parent
if Assigned(pElemParent) then
begin
// Resource protection
try
// Get the element 2 interface
if Succeeded(pElemParent.QueryInterface(IHTMLElement2, pElement2)) then
begin
// Check parent interface for zero client width or height
if (pElement2.clientWidth = 0) or (pElement2.clientHeight = 0) then
// QI for element 2 interface
result:=pElement.QueryInterface(IHTMLElement2, Element)
else
// We have the element we are after
Element:=pElement2;
end
else
// QI for element 2 interface
result:=pElement.QueryInterface(IHTMLElement2, Element);
finally
// Release the interface
pElemParent:=nil;
end;
end
else
// Return nearest COM error
result:=E_NOINTERFACE;
finally
// Release the interface
pElement:=nil;
end;
end;
end
else
// Return nearest COM error
result:=E_NOINTERFACE;
finally
// Release the interface
pDoc:=nil;
end;
end;
end
else
// Return nearest COM error
result:=E_NOINTERFACE;

end;

function GetDocumentSize(Browser: TWebBrowser): TPoint;
var pElement: IHTMLElement2;
begin

// Get the browser body element interface
if Succeeded(GetBrowserElement(Browser, pElement)) then
begin
// Resource protection
try
// Set result size
result:=Point(pElement.ScrollWidth, pElement.ScrollHeight);
finally
// Release the interface
pElement:=nil;
end;
end

end;

function CreateScaledImage(Browser: TWebBrowser; Scale: Double): TBitmap;
var ptActual: TPoint;
ptScale: TPoint;
begin

// Get actual size
ptActual:=GetDocumentSize(Browser);

// Apply the scaling to it
ptScale.x:=Round(ptActual.x * Scale);
ptScale.y:=Round(ptActual.y * Scale);

// Get the image
result:=CreateThumbnailImage(Browser, ptScale);

end;

function CreateThumbnailImage(Browser: TWebBrowser; OutputSize: TPoint): TBitmap;
var pElement: IHTMLElement2;
pRender: IHTMLElementRender;
bmpRender: Array [0..1] of TBitmap;
dwClientWidth: Integer;
dwClientHeight:Integer;
dwIndex: Integer;
dwX: Integer;
dwLastX: Integer;
bDoneX: Boolean;
dwY: Integer;
dwLastY: Integer;
bDoneY: Boolean;
begin

// Create resulting image
result:=TBitmap.Create;

// Set size
result.Width:=OutputSize.x;
result.Height:=OutputSize.y;

// Lock update
LockWindowUpdate(Browser.Handle);

// Resource protection
try
// Get the browser body element interface
if Succeeded(GetBrowserElement(Browser, pElement)) then
begin
// Resource protection
try
// Get the renderer
if Succeeded(pElement.QueryInterface(IID_IHTMLElementRender, pRender)) then
begin
// Resource protection
try
// Create images to blit the parts to
for dwIndex:=0 to 1 do
begin
bmpRender[dwIndex]:=TBitmap.Create;
bmpRender[dwIndex].Width:=pElement.scrollWidth;
bmpRender[dwIndex].Height:=pElement.scrollHeight;
end;
// Set render "printer"
pRender.SetDocumentPrinter('Bitmap', bmpRender[0].Canvas.Handle);
// Get client width and height
dwClientWidth:=pElement.clientWidth;
dwClientHeight:=pElement.clientHeight;
// Resource protection
try
// Set starting X variables
dwX:=pElement.scrollWidth;
dwLastX:=(-1);
bDoneX:=False;
// Loop while X not done
while not(bDoneX) do
begin
// Scroll
pElement.scrollLeft:=dwX;
// Get scroll
dwX:=pElement.scrollLeft;
// Check for (-1)
if (dwLastX = (-1)) then dwLastX:=dwX + dwClientWidth;
// Set starting Y variables
dwY:=pElement.scrollHeight;
dwLastY:=(-1);
bDoneY:=False;
// Loop while Y not done
while not(bDoneY) do
begin
// Scroll
pElement.scrollTop:=dwY;
// Get scroll
dwY:=pElement.scrollTop;
// Check for (-1)
if (dwLastY = (-1)) then dwLastY:=dwY + dwClientHeight;
// Draw to bitmap handle
if (pRender.DrawToDC(bmpRender[0].Canvas.Handle) = S_OK) then
begin
// Blit the image
BitBlt(bmpRender[1].Canvas.Handle, dwX, dwY, dwLastX-dwX, dwLastY-dwY, bmpRender[0].Canvas.Handle, 2, 2,SRCCOPY);
end;
// Update the Y variables
bDoneY:=(dwY = 0);
dwLastY:=dwY;
Dec(dwY, (dwClientHeight-4));
end;
// Update the X variables
bDoneX:=(dwX = 0);
dwLastX:=dwX;
Dec(dwX, (dwClientWidth-4));
end;
// Stretch draw the image to the resulting bitmap
StretchBlt(result.Canvas.Handle, 0, 0, OutputSize.x, OutputSize.y, bmpRender[1].Canvas.Handle, 0, 0, bmpRender[1].Width, bmpRender[1].Height, SRCCOPY);
finally
// Free the bitmap
for dwIndex:=0 to 1 do FreeAndNil(bmpRender[dwIndex]);
end;
finally
// Release the interface
pRender:=nil;
end;
end;
finally
// Release the interfaces
pElement:=nil;
end;
end;
finally
// Unlock update
LockWindowUpdate(0);
end;

end;

end.

CristianIgnat

ASKER

Thanks !!!

It works amazing!

Russell Libby

Glad to here. ;-)

Russell

Russell Libby

Cristian,
Were you going to close this question, or did you need further help?

Russell

CristianIgnat

ASKER

oh, sorry !
I thought I closed it!

THANKS !!!

Russell Libby

No problem, and thank you...

Russell